Shear-Loc® is the originator of the patented Instant Thumb Screw and all its corresponding knobs, screws, nuts and drives. Shear-Loc's assortment sets are complete with 340 pieces with multiple lengths and diameters, with thread sizes from #4 through 3/8". Shear-Loc manufactures proudly in the USA from their Laguna Hills, CA locations, and is part of the TTC Production family.