OTTO Excavator Parts Ex300 6Sd1T Thermostat Shell 1137130500 113713-0500 1-13713050-0 For Isuzu OTTO Thermostat Shell (EX300 6SD1T) - P/N: 1137130500, 113713-0500, 1-13713050-0. For Isuzu engines, ensures proper coolant flow and temperature control in excavators. Durable OEM replacement.