Perhaps this was general knowledge, but my DME had told me that the only difference between the AirFit P10 "For Her" and the basic AirFit P10 was the sizes of the pillows included. So when they accidentally sent me the Plain mask kit at my 6 month refill, I thought "Good -- it'll give me a chance to try the Large nasal pillows without having to order one".
I did try the large size, and I might actually like it. I'm still deciding about that. But I've compared the mask strap, and there is definitely a 1.5 inch or 2 inch difference in the head strap length.
So if you need a smaller head strap length, try ordering the "For Her" kit. It's purple rather than blue. The nasal pillows are Ex Small, Small, and Medium. With the plain kit, the nasal pillows are Small, Medium, and Large and the strap is blue.
Right now, I am awaiting a call-back from my DME, to see if they will order me the brand new "mask clips", part number 62962 which somebody else told us about here. The alternative is to attempt to staple the blue headgear to a smaller size. So we'll see. Or perhaps I'll buy the clips myself, from one of the vendors on our list here.
ADDED: Or, apparently my DME could decide to resend the whole mask kit, and send me the AirFit P10 For Her kit, which they should have originally sent. So now I have a spare mask, barring only one slightly too long blue head strap! Wow! Plus, I got to try out the Large nasal pillows which I had wanted to try. Maybe I ought to buy a lottery ticket today too .....