This is a five pin lock I recently got from ChemicalRobot on www.keypicking.com. It is a Yale, it has stainless steel key pins, one regular driver and four graduated spool driver pins. I call them mushroom spools since they are like a hybrid of both. The lip on the bottom of the mushroom spools made setting the four pins after the false set from pin five an absolute bitch. It is a great fun lock to pick and puts up a hell of a fight. Thanks again ChemicalRobot. I used a twist flex tension wrench, a Peterson Reach and a Peterson Gem.