Feuling HorsePower Plus Hydraulic Lifters / Tappets For Harley Whether you're looking to improve oil flow and reliability in a stock power plant or need serious cooling and oil volume for a built machine, Feuling's tappets are up to the task. Improved oil flow and precise CNC machining make them a dependable choice, and they are made in the Usa. Features: Performance hydraulic roller lifters dyno developed and track tested CNC-machined and precision ground When used with FeulingOil Pump, they will increase critical oil flow to valves, springs, rockers, shafts and valve guides Extend life of top end valve gear Can also be used for OEM replacements Sold in a set of four Made in the USA Note: Feuling recommends running a high volume oil pump, not required but can result in better performing lifters (Feuling does not offer an EVO oil pump)