Features a redesigned billet aluminum lock-up pressure plate designed to fit under the stock primary cover. Surface area is greatly increased and lever effort is kept to a minimum. Low profile design. Three different coil spring sets included to provide a wide variety of spring pressure options, allowing you to tune the clutch for stock to 200+ HP applications. Bolt on, no modifications required. Steel inner hub with bearing is also included to complete the unit. Billet aluminum pressure plate. Adjustable pressure arms increase spring pressure as rpm increase. Can be run wet or dry. Smooth, precise shifting. Comes assembled with bearing included. Made in the USA. Derby cover spacer #686-30-16100 is required. The spacer plate is NOT required if using Barnett derby cover #343-30-43015/343-30-44015..