Milwaukee 49-66-6720 SHOCKWAVE Impact Duty 1/4” Drive to 3/8” Drive Adapter The Milwaukee 49-66-6720 SHOCKWAVE Impact Duty 1/4” Drive to 3/8” Drive Adapter provides you with tool versatility. These adapters convert drive tools to be used with 1/4”, 3/8” and 1/2” drive tools and sockets. Milwaukee engineered these adapters with forged steel for durability in high torque applications. The laser-etched size markings allow for easy size identification. The dual-hole design and ring groove make for easy adapter attachment and removal. All Milwaukee® SHOCKWAVE Impact Duty™ Socket Adapters meet ASME industry standards.