The WORKPRO deep socket (WP274126) is a 6-point (hex) type, 21 mm size, 1/2" square drive. It is made of Cr-V steel with a mirror polished (chrome) finish and has an overall length of 78 mm – enough to reach bolts hidden behind other parts. Specifications: - Socket: 6-point (hex) - Size: 21 mm - Drive: 1/2" - Material: Cr-V steel - Finish: mirror polished (chrome) - Overall length: 78 mm