We're easing Gwendolyn into a new bi-pap mask little by little. The mask and headgear that she has been using for months is perfect, but we're having trouble finding a replacement for it so we're testing this one just in case something happens to her favorite mask. This mask is a Respironics Simplicity with headgear and since they don't make most of these sets for infants, Victoria had to modify the headgear to fit Gwendolyn's head — it now fits perfectly. Gwendolyn resisted a bit when we tried it for the first time last night, but she seems to be warming up to it today 