Through extensive research JBL developed a proprietary latex formula that delivers unparalleled modulus strength. Its called Nitro Rubber. This elastic super material is what puts JBL Nitro Bands in a league of their own. They’re designed to be the ultimate spearfishing propellant. Nitro Bands feature an exponential power to stretch ratio that delivers unmatched contraction. The result: maximum shaft propulsion. This means your shot goes from A-to-Fish before your target knows what hit it. Pull the trigger and let Nitro Bands do the rest. In addition to exceptional performance, Nitro Bands are designed for long lasting use. Nitro Rubber is anti-oxidants infused to help protect against damaging UV rays. Wishbones are made from either 302 stainless steel wire or coated triple core Spectra, depending on selection. Expect extreme strength and durability from Nitro Bands.