The JCB 336D3684 is a genuine OEM thermostat designed for various JCB machinery, including 3CX and 4CX backhoe loaders, Loadall telehandlers, Fastrac tractors, and JS series excavators. This essential engine component regulates coolant flow to maintain optimal operating temperature, opening at 82°C to ensure efficient engine performance and prevent overheating. Weighing 0.12 kg with dimensions of 95 mm length and 51 mm height, it is a direct replacement part for reliable thermal management.