Sentry Sprinklers Model GB-3100 and TB-3100 are bronze body Butterfly Valves that are bi-directional and suited for vertical and horizontal installation. The valve is the indicating type designed and listed for use in fire protection systems with a built in tamper switch suitable for indoor and outdoor use. The switch box is anti-corrosion with 10 mil (250μ) of fusion-bonded epoxy (FBE) coating. All other components are made of corrosive resistance materials.