The WORKPRO impact socket (WP413020) is a 27 mm hex socket with a 1/2" square drive. Made of chrome-molybdenum steel (Cr-Mo) – a tough alloy for impact loads. The special black finish protects against corrosion and wear. Suitable for ratchets, extensions and impact wrenches with a 1/2" drive. Specifications: - Size: 27 mm - Drive: 1/2" - Material: Cr-Mo, black finish