NIUNIU Socket AdaptersThis is a set of 4 pieces socket adapters specially designed for impact driver or wrench conversions. Most often used in the automotive and engine repair fields. Ideal tool for mechanics, engineers, carpenters or DIY enthusiasts. High QualityThese power tool sockets are made with high quality chromium-vanadium steel with heavy duty construction to ensure maximum durability and allows for long service life. With highly durable electrophoresis black coating finish, it is corrosion resistant to eliminate chance of rust for a long lasting time. Common JointsUniversal joints are flexible joints that allow you to use a socket with a ratchet, breaker bar, or extension. Detent BallsEach impact adapter is equipped with built in Spring-loaded detent balls to preventing them from being dropped during repairs. Delivery Quantity: 1 set of 5pcs, Package Contents: Only the above package contents, excluding other products. Size: 3/8 hole to 1/4,1/2 hole to 3/4, 1/4 hole to 3/8, 1/2 hole to 3/8, 3/8 hole to 1/2 (Reminder: The size is measured manually, please allow 1-2 cm measurement error) Colour: Black (Due to different monitors and lighting effects, the actual color of the item may be slightly different from the color shown on the picture.)