This Vibrant crankcase breather filter is perfect for engines, transmissions, oil, and gas tanks on high performance vehicles. Keep blow-by from entering back into your engine with these crankcase vent filters. These high quality oil breathers feature a cotton gauze element with a metal base and top for durability. Available with a 3/8", 1/2", 5/8", 3/4" or 1" inlet. For off road only.