The Grey Pneumatic 4038M is a 1-inch drive by 38mm standard-length, 6-point metric impact socket. Key Specifications Drive Size: 1" square drive Socket Size: 38mm (hex configuration )Length: Standard length Configuration: 6-point (helps prevent the rounding of fasteners) Material: High-quality Chrome-Molybdenum (Cr-Mo) alloy steel Finish: Corrosion-resistant black oxide coating Weight: Approximately 1.75 lbs