11 piece setBits are made from S2 steel1/4" and 3/8" driveSocket clip railHeavy duty useKincrome Socket Rail Sets are ideal for any application where a specific bit is required. Available in seven different varieties, these sets are complete with a rail for better organisation around the workshop. This Kincrome 11-piece Metric Hex Socket Set contains a range of blade sockets to suit a variety of applications. Made from ultra-tough S2 steel, and complete with a handy socket clip rail for 'out of the box' organisation, the Kincrome 11-piece Metric Hex Socket Set is designed with everyday trade use in mind making them perfect for any trade professional.1/4" Square Drive: H1.5, H2, H2.5, H3, H4, H4.53/8" Square Drive: H5, H6, H8, H10, H12