The 6531311M1 is a genuine AGCO radiator cap, specifically designed for various Massey Ferguson tractor models. This essential component maintains the correct pressure within the cooling system, preventing coolant loss and ensuring efficient engine temperature regulation. It is a direct replacement for original equipment, compatible with models such as the MF 135, 165, 240, and 590. This cap is also cross-referenced with several other AGCO part numbers, including 3617301M1 and 3617301M91, indicating its broad applicability within the AGCO family of brands, which includes McCormick.