Neiko 01362A Go-Through Screwdriver Set with Magnetic Tips, 8 Piece Heat treated, chrome vanadium steel blades construction provides excellent durability and strength with every twist Harden, sand blasted black magnetic tips are sharp and offers a non-slip fit for use on even the most stripped/rundown screws Square shaft, tri-lobular handles are slip-resistant and ergonomically designed for maximum comfort Go through drivers come in eight pieces in variety of sizes including: Flat5/16"X8", 1/4"X5", 1/4"X4", 3/16"X3"; Phillips: 1/4"X6" #2, 1/4"X5" #2, 1/4"X4" #2, 3/16"X3 #1 Unique contoured grip allows for opportunity to work with higher torque applications and ensure accuracy