3/8" Optical Punch Set ~ Punch size is 3/8". ~ Made of tempered steel. ~ Overall length is 2-3/4". ~ Body diameter is 3/8". ~ Pin length is 1.85". ~ Lens magnifier power is 9x. ~ Allows you to punch layout points within .002" of location easily. ~ Even the inexperienced can punch accurate holes every time with this set. ~ It is indispensable when doing critical layout work. ~ Just look down the magnifying lens and align the cross hairs with the mark on your work piece. ~ Replace the magnifier with the supplied punch and give it a tap. ~ Punch set includes 3 components: a bullseye and cross hair lens, a 120 degree center punch made of tempered steel, a precisely manufactured aluminum main body and a fitted case.