Quick answer: These are genuine ResMed replacement port caps, supplied as a 2-pack (part 16570). Many Mirage-series masks have small ports on the frame — used for connecting supplemental oxygen or a pressure line — and the port caps seal them closed when they aren't in use. A missing or loose cap means air escapes from the port, which shows up as pressure loss, whistling, or a mask that won't hold its seal.
What's included
- 2 × ResMed port caps (part 16570)
Mask, frame, cushion, and headgear not included.
About these caps
The ports on a Mirage mask frame exist so that supplemental oxygen or a pressure-monitoring line can be connected when a clinician prescribes it. Most users never use them — which is exactly why the caps matter: with nothing connected, the ports must stay sealed, or pressurised air simply leaks out.
Port caps are small, made of soft plastic, and removed during cleaning — so they're among the most commonly lost mask parts. The symptoms of a missing cap are easy to misread: a faint whistle, therapy that feels weaker than usual, or persistent leak alerts that don't improve no matter how you adjust the headgear. A 2-pack replaces both caps, or gives you a spare.
Key features
- Genuine ResMed port caps — correct fit and sealing.
- 2-pack — replace both, or keep a spare.
- Seals unused mask ports — prevents pressure loss and whistling.
- Easy to fit — pushes into the port; no tools.
- Inexpensive fix — restores full pressure delivery for very little.
Specifications
| Specification | Detail |
| Product type | Replacement port caps |
| Pack quantity | 2 |
| Function | Seals the oxygen/pressure ports on the mask frame |
| Compatible masks | ResMed Ultra Mirage / Ultra Mirage II |
| Included | Caps only |
| Prescription | Not required |
| ResMed reference / SKU | 16570 |
| Brand | ResMed |
Frequently asked questions
What do the port caps do? They seal the small ports on the mask frame when nothing is connected to them, so pressurised air doesn't escape.
How many are in the pack? Two.
What are the ports actually for? Connecting supplemental oxygen or a pressure-monitoring line, when prescribed by a clinician.
My mask whistles or feels weaker — could this be why? Yes — a missing or loose port cap is a common and easily overlooked cause of pressure loss and whistling.
Which masks do these fit? ResMed Mirage-series masks with frame ports — please confirm against the packaging, or contact us at (718) 735-3400 with your mask model and we'll check.
Do I need a prescription? No — replacement mask parts like this do not require a prescription.
Can I get them delivered in Brooklyn or shipped nationwide? Yes — Task Supply Corp offers USPS shipping throughout the continental U.S., plus local pickup and delivery in Brooklyn and all five boroughs of New York City.
Use these parts with a compatible ResMed mask according to the mask's user guide. Keep unused ports capped during therapy.