A no pin, impact adaptors set which includes 1/4", 3/8", & 1/2" adaptors. This set has a ball with flats, instead of a pin in order to maximize torque transfer. It also reduces the chances of breaking. The pieced work as both a joint and straight connector.
No pin but a ball with flats maximizes torque transfer.
3 sizes means there is an adaptor for each size.
Use with impact to save time.