Sierra International 18-0540 Exhaust Leg Rubber Seal The Sierra 18-0540 Exhaust Leg Rubber Seal is interchangeable with the following: GLM 85830, Evinrude/Johnson 320936. Each Sierra product meets or exceeds the original equipment part it replaces. Sierra Exhaust Leg Rubber Seal Meets or exceeds the original equipment quality Sierra part number: 18-0540 Interchangeable with the following: GLM 85830, Evinrude/Johnson 320936