UI Control Knob for PR System One REMstar Series CPAP & BiPAP Machines

Philips Respironics UI Control Knob for PR System One REMstar Series CPAP & BiPAP Machines

4.62 Average Rating of 56 Reviews Read Reviews



The System One UI Control Knob is dark, charcoal gray in color with a silver inlay around the rim. The sides of the knob are ridged to make them easy to grip.

COMPATIBILITY: This Control Knob comes standard with all "60 Series" System One CPAP & BiPAP machines -- REMstar Plus 260, REMstar Pro 460, REMstar Auto 560, BiPAP Pro 660, BiPAP Auto 760, etc. It can also be used to replace the lighter gray Control Knob found on all "50 Series" System One CPAP & BiPAP machines -- REMstar Plus 250, REMstar Pro 450, REMstar Auto 550, BiPAP Pro 650, BiPAP Auto 750, etc.

INSTALLATION: When an old UI Knob is removed or lost a small metal ring from inside of it can sometimes get stuck on your CPAP machine's knob post. If that ring is present the new UI Knob will not fit properly onto the post. To fit the new UI Knob properly remove the metal ring, either from the post or from inside the new knob, before inserting the new UI Knob onto the machine's knob post.

Product Information

  • Manufacturer Philips Respironics
  • Part Number(s) 1099581
  • HCPCS Code E1399
  • GTIN / UPC Code 00673681230587
  • Warranty 30 Days
    Warranty Notes: Warranty applies to primary item. Accessory and parts warranties may vary. Review manufacturer's documentation for full details.
  • Country United States of America (Typical Origin)


Average Rating of
Total 56 Reviews
  • Knob-Job

    went well, as advertised, no issues or complaints
    Written by rjcataniajr, 2020-01-25
  • Knob for CPAP machine

    Didn't know for sure I was purchasing the correct knob or not. Received the knob and advise about ring still being on was helpful. Took ring off with small screwdriver and knob went on easily. Was surprised that it did take awhile to receive. But over all pleased
    Written by john09201947, 2019-12-22
  • Same knob, different size

    I ordered a knob for my exact model. It doesn't fit, list a hair too small to fit.
    Written by drmrboy314, Maryland2019-12-14
  • Exact Fit

    The knob was an exact fit. Shipping speed was on par with anyone else and the shopping experience was great!
    Written by Help-5720, Michigan2019-11-29
  • Good Value!

    Item was priced well and including fast, first-class mail shipping. Would purchase from DirectHomeMedical again.
    Written by dmatuszak2, 2019-08-05
  • Works great

    Works great, plus the directions on the bag were very helpful. Thank you very much.
    Written by melbacarden, 2019-06-20
  • Solved a perplexing problem!

    I was so disappointed when my $3500 BIPAP machine was significantly hampered by a failed plastic knob. After searching the Internet I found this inexpensive solution, even with free shipping. The replacement knob put my machine back to its full normal function.
    Written by jamesldavenport, 2019-05-05
  • replacement knob didn’t fit

    my machine is listed on the compatibility list, but the replacement knob does not fit.
    Written by Quisquillosa, CA2019-02-14
  • Great place to do business with!

    Ordered a new control knob online and received it lightning fast. Great item at a great price!
    Written by dayjed, 2019-02-08
  • Great Service

    Part came quick and at a good price.
    Written by chrishayter, 2019-01-27
  • Perfect

    The knob broke at 4 AM. I ordered the replacement at 4:30 AM. It arrived 54 hours later.
    Written by wawinch-14515, 2019-01-03
  • Delivered promptly and fit perfectly

    It appears to be genuine OEM replacement part at a better price than other sites I checked. Delivered promptly and was a perfect fit.
    Written by jkdub, 2018-12-23
  • Perfect fit

    The control knob on my 60s series Respironics bipap broke off. After a little bit of searching, I found DirectHomeMedical.com. The knob was less than eight dollars and the shipping was really quick. This replacement control knob was a perfect fit. I am very happy with it.
    Written by bigbearsfan-98398, 2018-12-04
  • Had difficulty getting it on the machine

    It wouldn't seat well. Was afraid to push it harder in case it would break. Any input. It's just sitting on top right now enabling me to use it but it is not securely fastened.
    Written by cadgator, 2018-11-09
  • Just what I needed

    Order easy to place, came in on time and fit my machine perfectly. Will use vendor again should need arise.
    Written by jsl1-39463, 2018-10-06
  • Knob

    Very happy to be able to get a replacement knob thanks
    Written by quiverful, 2018-10-02
  • Excellent

    Great price fast delivery would use them again for more supplies I would recommend to my family and friends
    Written by Acevette63, 2018-09-15
  • Great service

    Had what I needed and fast shipping.
    Written by karens10, 2018-08-13
  • Fit great, instructions spot on

    Fit great, instructions spot on, I had to pull off the metal ring from the shaft as noted in the instructions. It was quick and easy.
    Written by opk-96279, 2018-08-10
    perfect fit just what I needed, very quick service
    Written by jbenner-3611, 2018-08-07
  • control knob

    fit perfectly identical too the old one
    Written by Fesl1968, 2018-06-16
  • Perfect fit!

    Just what I needed! Thanks
    Written by ginabina317, 2018-05-14
  • Quick service

    Great price and super quick delivery.
    Written by grantchew, 2018-04-18
  • All good

    Exactly as described and the shipped quickly.
    Written by beamman, 2018-04-12

    Written by rohitp999, 2018-04-09

    DHM Notes: Hello, We're sorry to hear you're having problems with the knob we sent. If your machine is a Philips Respironics System One CPAP or BiPAP then you have the right knob and it may just take a bit of effort to get it to fit properly. When an old UI Knob is removed or lost, a small metal ring from inside of it can sometimes get stuck on your CPAP/BiPAP machine's knob post. If that ring is present the new UI Knob will not fit properly onto the post. To fit the new UI Knob properly remove the metal ring, either from the post or from inside the new knob, before inserting the new UI Knob onto the machine's knob post. Please let us know if you have any additional questions or concerns. Take care!

  • control knob

    It arrived on time and in good condition. It doesn't quite fit down as far as the old one but it works fine.
    Written by janiephil, 2018-02-13

    DHM Notes: Hello, When an old UI Knob is removed or lost, a small metal ring from inside of it can sometimes get stuck on your CPAP/BiPAP machine's knob post. If that ring is present the new UI Knob will not fit properly onto the post. To fit the new UI Knob properly remove the metal ring, either from the post or from inside the new knob, before inserting the new UI Knob onto the machine's knob post. Take care!

  • Good Purchase

    knob did not fit perfectly but it did work for what I needed it for.
    Written by quijano-29290, 2018-02-09
  • Fits great

    My old knob broke and needed replaced. It fits.
    Written by ddgm23rd, 2018-02-02
  • Perfect for our CPaP machine

    Thought we may have a hard time finding the knob after ours broke but found the exact knob for an excellent price. Shipping was speedy. Only positive comments because our shopping experience was very good!
    Written by debnegri53, 2018-01-23
  • Works Great

    Works just like the original
    Written by PinoyMuscle, 2017-09-19
  • Directions would have helped

    Got the part, on time and as expected. Looks just like the old one. Would have rated it a 5, except that I didn't get any installation instructions with the part. I did eventually find them online, and once I removed the nearly invisible portion of the old part, it worked fine.
    Written by Matt, 2017-09-07
  • Couldn't find this anywhere else!

    I couldn't find this knob for my CPAP machine anywhere else and DirectHome Medical had it at a reasonable price!
    Written by Carl, 2017-08-15
  • Prompt service...right part

    Prompt service and the right part; can't ask for more. An older C-PAP I use when traveling. I shoul have checked here first.
    Written by J Nylund, 2017-07-29
  • Replacement knob

    The knob arrived very promptly as promised. It was what I needed but I am having difficulty attaching it permanently. It's just sitting on top loose.
    Written by Sandy, 2017-05-06
  • Bob from Wisconsin

    The knob was just perfect!! They are made so cheap but what can you say !!
    Written by Bob K, 2017-04-30
  • Broken Part

    I ordered a replacement part for my CPAP. It arrived a day early and was the correct part.
    Written by Jerry, 2017-04-14
  • Knob review

    It's a Knob. What else can I say?
    Written by Knob user, 2017-04-10
  • Knob

    Was just what I was expecting, easy to replace as well
    Written by Derek Wright, 2017-04-09
  • My c pap

    Fit perfect
    Written by Bill Raybold, 2017-02-23
  • What a Knob

    First of all, I was delighted that the knob was available. My only problem was figuring out how to remove the clip to allow the new knob to be applied. I saw these reviews and took the advice and removed the clip from the post. (Was afraid of damaging the knob) With a little perseverance I finally succeeded in removing the pin. The knob then fit like a glove.
    Written by anneRkissed, 2017-02-04
  • Exact Knob

    The right knob for my machine. Had to remove old lock ring (as advised when purchased) from machine to attach new one.
    Written by Machine User, 2017-01-10
  • knob

    The knob doesn't fit properly on the stem and so it wobbles
    Written by Tim, 2016-12-09
  • Cpap machine control knob

    This item was received in a timely manner in good condition. It was the correct knob for my machine. Reasonably priced.
    Written by Skeet, 2016-11-20
  • It's a perfect replacement.

    I broke the original knob off and needed a replacement. After shopping around, this seemed to be the best value. I had a little difficulty removing the metal insert from the old broken knob out of the machine but once it was all removed this unit fit perfectly.
    Written by Guy T, 2016-11-04
  • Great service! Arrived sooner than expected. 😊

    I wish I had known about being able to buy this little piece for my CPAP. The knob broke off a year and a half ago. Then my CPAP provider said they didn't take care of stuff like that. So glad I found Direct Home Medical!
    Written by DYS, 2016-10-29
  • control knob

    Had to replace --this one fits well
    Written by AJC, 2016-10-22
  • parts

    lucky to find a knob for cpap machine at a reasonable price, shipping was prompt
    Written by vern, 2016-09-27
  • Perfect Replacement Knob

    After ordering the replacement it arrived within several days. The price isn't bad and the shipping is free! My old metal ring that is referenced in other reviews was the biggest issue. I was able to removed the old metal ring from the post with a small paper clip. I finally got leverage on the curved side of the post. There were a couple of indentations that turned out to be slits in the metal ring that allowed me to get the leverage. Overall, great experience!
    Written by Hal, 2016-01-06
  • Another good seller

    Quick, precise, and inexpensive. You just can't ask for more.
    Written by Na, 2015-11-27
  • Replacement knob

    Fit like new
    Written by William, 2015-11-23
  • Right Product

    Some how the knob on my machine broke. I looked at several websites but decided to purchase from Direct Home Medical for price. Shipping was within 24 hours of purchase and delivery within 72 hours, best service...
    Written by BA Greene, 2015-08-31
  • My supplier sent me to this website

    My BiPap supplier said they did not have the knob but gave me direct home medical's website address. Found what I needed quickly, the price was right and delivery was quick. Knob fit my System one machine perfectly.
    Written by Wally H, 2015-07-23
  • Cpap Control knob

    Exactly what I expected and quick shipping.
    Written by Richard K, 2015-07-13
  • Perfect!

    This knob worked perfectly to replace one broken on a plane trip. Make sure that the metal insert from the old knob is removed from the CPAP first so that the new knob will fit.
    Written by Ed L, 2015-06-09
  • Clearly OEM quality.

    Put it on. It works just like the original.
    Written by Joe W, 2015-06-02
  • Just what I needed

    The knob was an exact match, I couldn't get it on at first, then realized the metal sleeve from old knob was stuck on the shaft. It was a little tricky, but if you're having trouble installing this, most likely that's the problem. Service was excellent, received it in a few days.
    Written by Bob, 2015-03-09