characteristic: High hardness, chrome-plated surface treatment to corrosion resistance. Suitable for automobile industry, home maintenance, manufacturing and construction. Suitable for screwdriver or electric screwdriver handle tool, which can be installed on the hexagonal handle to become a square head. Allows you to match plugs, ratchet handles, extension rods and other accessories to the size of the equipment. Square head design of four-corner arc-inner corner design of arc, with slightly inserted holes, strong locking force, not easy to slip and convenient to use. Carbon black phosphating treatment-the surface is treated with carbon black phosphating treatment, which is beautiful and elegant, impregnated with antirust oil and can prevent rust. describe Name: pneumatic sleeve set Material: steel Plastic Box colour: Black Package Contents: 1 x Pneumatic sleeve set Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.