The Tekton 15-Piece Hex L-Key Set includes 7/16-3/4 in. and 11-19 mm L-keys with hex key racks. The L-keys are made from 6150 chromium vanadium steel that's heat-treated to 44-50 HRC and coated with a durable manganese phosphate finish that's resistant to corrosion. We measure our hex key tolerances in two ways, from point-to-point and side-to-side, to ensure the highest standards of dimensional accuracy and consistency. The L-key sizes are marked with a high-visibility laser marking and a stamped marking. In the included racks, the keys rest in hex-shaped slots, making it easy to take the tools in and out without resistance. Each slot in the rack is made to fit a specific L-key size. The handles on either side of the racks make it easy to lift out of a drawer. The racks are made from 12 gauge steel with a textured powder-coat finish and include size label sheets.