THIS IS A ROTARY CUTTER KIT. 1/4" Retractable spot weld pilot 3/pkg. Includes 1/4". 5/16", 3/8", 7/16", 1/2", 9/16" & 5/8" cutters, arbor & 3 extra pilots. Blaircutters provide fast, accurate holes in materials up to 3/16" thick. Blaircutters are annular cutting tools that cut around the edge of the hole & eject the center as a slug. Spring loaded pilot "pops" the slug from the cutter. Packaged in a blow molded case.