To apply- put  at the junction of the neck and brisket.  First clip/shave hair with clippers and use the punch applicator to put a hole through the loose skin. The U-shaped plastic- coated hasp is placed through the hole and the tag placed over the hasp. The ends of the hasp are bent back and over to hold the tag in place.

Boc-Loc Dewlap tags come complete with hasp.