Cal-Van Tools 3/8 inch-1/2 inch Twin Spin Drive Converter can be used to use a 3/8 inch drive socket on a 1/2 inch ratchet. Or a 1/2 inch drive socket on a 3/8 inch ratchet. It can withstand a higher torque than traditional adapters. It can be used as a small extension or hand drive for tight access. It is patented.