This sandwich adapter was designed to one give a non-thermostatic option to consumers with high performance engines with 2 3/4" filter landings and two to fit import vehicles with 2 1/2" diameter filter landings. Made using high quality die-cast aluminum with 1/2" NPT ports this adapter provides external oil lines to allow the addition of an engine oil cooler. It installs between the stock engine oil filter landing and the oil filter. Stock filter is retained. Kit includes sleeve nuts and brass hose barb fittings.