SHOCKWAVE impact duty™ insert magnetic nut drivers are engineered for extreme durability and up to 10x life. Made from proprietary steel and heat treated to control hardness, it feature a powerful magnet allowing for a secure grip and unyielding bit engagement. The bits feature colour-coded rings for quick and easy size identification and a chamfered edge to allow for fastening in tight spaces. Designed for use with SHOCKWAVE magnetic bit tip holders 2.36, 3, 6, 12, 30° Knuckle™ pivoting bit holder and all bit tip holders. Set consists of 1/4, 5/16, 3/8, 7/16, 1/2 inch insert magnetic nut driver.