EXTERNAL STAR SOCKETS 13-Piece set: 5 pcs 1/4" Drive E4, E5, E6, E7, E8 -6 pcs 3/8" Drive E10, E12, E14, E16, E18, E20 -1 pc Adapter 3/8“ to 1/4 -1 pc Adapter 1/4" to 3/8 DURABLE - Drop forged and heat-treated advanced Chrome Vanadium steel. Hardened to reduce wear-outs and Increase turning power. LONGEVITY - Complete rust and corrosion resistance with the active Manganese Phosphate treatment for enhanced durability under any circumstances. COMFORTABLE - Insert smoothly onto fasteners with precision chamfered ends. The laser-etched sizes will make identifying your sockets a breeze. 100% RISK-FREE – Meet & Exceeds ANSI (The American National Standard Institute) and backed by our Lifetime Limited Warranty for your complete peace of mind.