This is the Highest Quality Rebuild kit on the market, built by Marine Hydraulic Specialists. The OEM kit uses faulty seals that fail and leak within 10-15 years. If you cannot rebuild your unit we give you the option to send it into us for rebuild and we will credit the cost of this rebuild kit towards getting your unit professionally done by us, all of our rebuild services come with a Full 2 Year Warranty. This kit use materials like Viton and or High Grade Urethane Seals to ensure you will only have to rebuild your unit once for the life of the motor. We give you a diagram of the unit basic instructions and helpful tips. Build your unit once and for all with peace of mind just like the professionals. Thank you very much.