My mask experience was simlar but the cut holes for my eyes, nostrels and mouth. Plus I had to put the "popsicle" in my mouth during radiation. It kept my mouth and tongue exactly in the same position during treatment.

I also got the "strap" to pull my shoulders out of the way during the radiation process. This is accomplished by tying the strap to a wrist running down below your feet with your knees slightly bent and up to the other wrist. Then by straightening you knees it pulls down on your arms, shoulders, etc. Fun times!