Dzus Fasteners? I work with them everyday. they are okay when new but after a bit of use.... they are designed to save time and to make sure stuff isnt overtorqued but after a bit of use they are just dumb. usually-well mannered people start using swear words and even invent some, and to be honest, they are pricey. Use the money on a good snap-on electric screwdriver, get some anchor nuts (nylock type) and forget these stupid things.