JBL's unique latex formulation and dip manufacturing process delivers radical modulus strength. The power curve increases as bands are stretched for optimum performance. Special anti-oxidants help protect against harmful U.V. rays, prolonging sling life. Wishbones are 302 stainless wires that provide superior strength and durability, 9/16" diameter X 20" (14 mm x 510 mm) long. Sling is for JBL6W44, JBL4D44 and JBL4D22 Spear Guns.