The Carlyle 8-pc Screwdriver Set is part of the NAPA line of screwdrivers designed to help cover the needs of professional technicians. The screwdriver shafts are constructed of silicone vanadium chrome magnesium (SVCM) metal, a unique blending of key alloys, which offers hardness for added strength plus an elastic feature that prevents the screwdriver blade from breaking when overstressed. Each Carlyle screwdriver contains PP/TPR comfort grip handles, and certain models have hex bolsters on the shafts for added torque application along with vapor blasted magnetic tips for maximum convenience.