Putting ResMed Air Fit P10 on in the dark

[Sultec]

The pillow mask works only if one puts it on properly. It is clearly marked but one can't see the marking in the dark. The proper orientation has a slightly deeper curve on the bottom. One can also tell by the air flow through the mouth when it is on properly.
Is there any other way of telling, in the dark if one has it on right?

[C0mbe]

I can usually tell by touch whether I have it correct. The mask curves downwards towards the chin when on correctly vs up when on backwards and it feels quite awkward. Failing that, I shine my phone at the mask and find the marking!

[Crimson Nape]

Looking down from the top, the P10 is slightly bowed. The concave side goes toward the face, In the dark, you can easily locate the correct orientation by placing your thumb in the concave area,

[jaswilliams]

In the concave area you can feel the smooth silicone where the mask size is stamped

[Sleeprider]

The pillow openings converge at the top and are wider at the bottom. This is easily felt by sliding your finger through the middle of the openings.

[eplantz]

I put a smnall piece of black duct tape on the left siude of the headband. i can feel that in the dark bedroom so i know which way is which.

[AndyB]

The pillow openings converge at the top and are wider at the bottom. This is easily felt by sliding your finger through the middle of the openings.

Ditto -- this is quick & easy.

[Abbey sews]

I find establishing the curvature of the P10 in the middle of the night challenging, so I use the raised Resmed lettering on the diffuser. It is on the outside, away from your face. Hope this helps.

[Snoring Bear]

On the top side of the mask where the hose enters it, there is an extra hard plastic lip about 1/2 inch deep or so between the hose and the mask. If you feel the bottom of the tube/mask, there is no plastic lip at all. This makes it very easy to make sure you're putting on your P10 the right way in the dark. - I hope this helps someone.

[NotADr]

I put a smnall piece of black duct tape on the left siude of the headband. i can feel that in the dark bedroom so i know which way is which.

Exactly what I did, except I used medical tape, and wrapped it around the part of the split strap that I wear toward my forehead.  In the dark, it's easy to feel which section of the split strap should be toward the front of my face, while the other section goes around the back of my head.  I've submerged it many times and the tape hasn't yet come off.