Jump'In Blue Steel D-Ring Bit w/ Double Joint & Copper RingsComposition : Verdun bit, 16 mm barrel in Blue Steel and 100% copper rings. The Blue Steel alloy which covers this range of Jump'In bits is composed of 54% carbon and 46% manganese . Blue Steel bits oxidize on contact with air and humidity . A thin layer of sweet tasting rust appears, which naturally stimulates the production of saliva . In salivating more, the horse makes more contact on its bit . In this oxidation process the color will change to