Patented U-shaped design.Open end angle 15° with a slimmer head for more accessibility.Large and one-directional size marking for easy identification.Chrome plated micro-matte finishing provides high quality surface.High-performance alloy steel.Less wear on fastener with the large contact surface area of the jaw.Optimised legibility and identification with high-clarity imprint.Standards: ISO 691, ISO 1085, ISO 10102 and ISO 3318