A Sandwich Plate lets you add an oil cooler (sold separately) without relocating the oil filter. The plate installs between your engine block and spin-on oil filter and gives you inlet and outlet ports. All of these plates are designed to use the same filter the engine originally used.
These sandwich plates have an internal bypass valve to reduce pressure in the cooler when the oil is cold (you should still take car to avoid revving the engine too high before the oil has warmed up). All are 1" thick and have 3/8 NPT female ports. All have 2 1/2" diameter O-ring seals (Part Nos. 1231-13/16x16 and 1231-20x1.5 also have 3 1/8" diameter O-ring seals). Choose the thread that matches the oil filter mount on your engine.