Features and Benefits:?Designed for use with Milwaukee SHOCKWAVE? magnetic bit tip holders?Strong magnetic for secure grip?Color-coded band for easy size identification?The Milwaukee 49-66-4512 contains 3 nut driversThe Milwaukee 49-66-4517 1/2 in. 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, the SHOCKWAVE? impact duty magnetic nut drivers feature a powerful magnet allowing for a secure grip and unyielding. Bit engagement. The bits feature color-coded rings for quick and easy size identification and a chamfered edge to allow for fastening in tight spaces. Designed for use with Milwaukee? SHOCKWAVE? magnetic bit tip holders 2.36 in., 3 in., 6 in., 12 in., 30? knuckle? pivoting bit holder and all bit tip holders. The pack contains 3 nut drivers.