Dermal Therapy Blistop is a blister prevention spray that creates an invisible layer of film to protect the skin on feet and hands where blisters can occur from friction.�Convenient and easy to use, Dermal Therapy Blistop stays in place and won't rub off easily or leave residue on your socks and shoes. It acts like a second skin and is totally transparent so you are able to wear the shoes of your choice and feel confident and pain free all day long. Protects feet (or any other areas prone to friction) from blisters. Is water resistant, allows the skin to breathe and provides up to 50 applications in one can. The essential in every women's handbag!