Derale 25783 Low Profile Pressue relief Sandwich Adapter with 3/8″ NPT Ports and 3/4″-16, 13/16″-16, 18×1.5mm, 20×1.5mm + 22×1.5mm Filter Threads. At only 1″ thick, this high quality aluminum low profile sandwich adapter features 3/8″ NPT ports and pressure relief valve and provides external oil lines to run an engine oil cooler while dropping the factory oil filter only 1″ lower than stock. Designed to be used on engines with 3/4″-16, 13/16″-16, 18×1.5mm, 20×1.5mm + 22×1.5mm Filter Threads. Provides external oil lines for oil coolers without relocating the factory oil filter. Cast form high quality aluminum. Maintain factory equivalent oil filter. Built-in pressure relief. Low Profile Sandwich Adapter with 3/4″-16, 13/16″-16, 18×1.5mm, 20×1.5mm + 22×1.5mm Filter Threads. Includes sandwich adapter, sleeve nut & O-ring. Specifications Adapter threads sizes 3/4″-16, 13/16″-16, 18×1.5mm, 20×1.5mm + 22×1.5mm Filter Threads. Adapter o-ring size 2-1/2″, 2-3/4″. Adapter thickness 1″. Adapter inlet size 3/8″ NPT