Face masks must be pressed tightly against the face to make a tight seal in order to prevent virusesfrom simply being drawn around the mask and getting into the nose and mouth. Sometimes single strapface masks are hard to get tight enough. Even masks that supposedly have adjustable straps on themask often seem to slip. This is a simple device that you can wear in the back of your head to tighten thestraps.To use it, place it on the back of the head with the strap first going through the pegs with two pegs oneach side of the mask. Then wrap the strap around and around the pegs in any direction until the maskis tight.