depending on what kind of mask your using an all, it should just fit on there. however sometimes you need to use addative like. Velcro. some people use Rare earth magnets, placed inside the mask with foam behind it so it doesnt cut the mask. hope this helps.
Hey there! I'm new here too, and I just found a solution: HALF MASKS! Half mask is that it has all the parts of a Pred's head except for the face (for easier breathing). The downside of using that mask is that you CAN'T take off the bio mask for the cool Pred unmasking himself action. They're not as expensive as full masks but if you want to be more comfortable in the costume, a half mask is the best way to go with wearing your bio mask. Hope this helps fellow hunter.