Mares Pure Instinct Razor Carbon Spearfishing Fins Blade made out of 3K pre-impregnated carbon fibers.Designed to be worn with a 3 mm neoprene sock Variable side ribs to support and optimize flex and channel thrust Ample 22 degree angle of blade natural extension of the leg; Blade: 880mm Manufacturing process with continuous vacuum in autoclave allows consistent quality for absolute reliability Unbeatable performance, lightweight design, Makes fining easier almost effortless