M20 x 1.5 oil filter sandwich plate & fan thermostat switch. Powers electric fan when turn-on temperature is reached. 3 total ports for oil pressure or other temperature sensors. Sandwich plate installs between engine block and oil filter. Installs when gasket diameter of your oil filter is 3” or less. Features: (1) Aluminum Sandwich Plate Adapter (3) 1/8-27 NPT Female Thread Ports (1) M20 x 1.5 Thread (3) 1/8-27 NPT Port Plugs (1) O-Ring for a Leak-Free Seal (1) Fan Grounding Thermostat Switch