Jacobs Chuck hex bit adapter chuck. Converts an impact driver into a drill. Quick change chuck attachment enables impact drivers to be used in drill applications. Fits all round shank bits. Ideal for drilling holes and hard-to-reach spaces. Locks the chuck into the hex bit socket. Provides a positive locking mechanism which prevents loosening in hammer and other high vibration applications. Plastic front and metal rear sleeves for greater durability. 1/4-inch mount. 3/8-inches capacity.