Recessed edges.
Socket openings are designed to reduce fastener rounding.
Chrome vanadium alloy steel construction for strength and durability.
Polished nickel chrome plated finish resists corrosion.
12pt Sizes: 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4" and 13/16"