heat-treated steel with flexible spring steel shaft anti-rust and inch shank and 250/350mm length. Flexible shafts allow improved access in tight space maintains excellent rotational torque-transfer from to socket. Spring-loaded balls detents in to parts from slipping into machineries.Square drive radiuses corners reduce tool and socket wear. Flexible Socket works in areas that conventional screwdrivers can't reach solve the repair the car engine stricture uninstall screw easily. Equipped with a wrench clamping grooves which can be clamped by a wrench. When there is wrench it can be used to clamp the wrench. The extension rod turn the sleeve.