Milwaukee SHOCKWAVE Impact Duty Socket Adapters are engineered for extreme durability and up to 10x life. SHOCKWAVE Impact Duty Socket Adapters are made from proprietary steel and heat treated to control hardness. 1/4" Hex 3 pack Shockwave set are designed to be used with a 1/4 impact driver. Set includes (1) 1/4 in., (1) 1/2 in., and (1) 3/8) in. socket adapter.