Genuine Land Rover Part Supplied. Including the hard to source O Ring that must be changed. Otherwise likely to leak.

Other Suppliers do not supply the O Ring

The thermostat regulates the flow of coolant from the engine to the radiator. Over time, the thermostat may fail to open or close or may begin to leak, either from a crack or the seal, if you notice that the coolant temperature is staying cold, overheating or any leaks from the cooling system in your Land Rover, get it checked out immediately.