Twin Air Exhaust Plug "Large", Diameter 27mm to 50mm (with Strap)Proprietary soft rubber material featuring fibreglass reinforcement that overlays a durable plastic base. The outer rubber material floats on the plastic base, allowing you to twist the plug into the exhaust creating a leakproof seal. The Twin Air lanyard attached makes it easy to find and store. Offered for 2 or 4 stroke exhaust systems. Features: Outer rubber material floats on the plastic base and allows you to twist the plug into the exhaust