Performance Tool Mechanics Products W30937 7 Piece Impact U Joint & Adapter Set Adapter sizes: 1/2 to 3/8", 3/8 to 1/2", 3/8 to 1/4" and 1/4 to 3/8". U-Joint sizes: 1/4, 3/8 and 1/2". Polished nickel chrome plated finish resists corrosion. Lifetime warranty. Chrome vanadium alloy steel construction for strength and durability. Impact Rated