When you are doing an "adjustable comb conversion" to a gunstock, this is a quick and easy way of marking the exact location for your comb bushing. After the saw cut and inletting of comb plate, place the transfer plate in the inlet and set the comb piece in place and press down hared, or smack-it with heel of hand. Plates are andodized aluminum with harden steel punches. Comes with a removing screw.