This a replacement end cap for you Single ram E-tec This cap contains the Groove that is required on Gen1 style E-tec Single Ram Units The Gen2 style cap if used on a Gen1 will cause the plunger relief valve to break and send metal throughout the system and causing leak down issues. We Use High Grade Viton Seals Rather Than Bio-Degradable Seals (why would you use Bio-degradable Seals?) This is a end all solution to your leaking end cap. The OEM kit P/N: 5008985 uses OXO Biodegradable seals that are set to fail within 6-10 years this is planned obsolesce. At Five Star Marine we take a completely different route using the Highest Marine Grade Aluminum and Hard Anodizing it for durability and extra corrosion protection. The seals we use are of the very highest quality and are designed to last 15-20 years rather than 6-10. You won't find Higher Quality Marine Parts We Only Choose The Best Materials Because The Repair Should Only Be Done Once. All End Caps/Glands are made from High Quality Aircraft Grade Aluminum Produced On Precision Computerized CNC Machines All Aluminum Parts Are Hard Anodized Using A Military Grade Type 3 Hard Coat (The Same Coating Used On Military Style Weapons) & Fitted With Viton & Or High Grade Urethane Seals Depending On The Applications Pressure / Sealing Requirements. We always chose the best quality methods and materials when producing anything aftermarket. The True American Way Is Quality Over Quantity. We produced these products because of the large volume of Marine Hydraulic Units we Rebuild and Remanufacture from all over the Country & World we are now offering them to the public at fair market price despite the very high cost of having quality parts manufactured in this day in age. All Of Our Products are Assembled In The USA and mostly sourced domestically whenever possible keeping the jobs here at home. We offer A 2 Year Warranty On All Of Our Products and Services