Replaces MerCruiser's R/MR/Alpha One I/O up to 300HP 3 year NO FAULT warranty!!! The three year fault-free warranty covers any damage to the drive that requires it to be repaired or replaced including failures resulting from lack of oil, fishing line, impact, neglect, and other abuse. Sterndrive Engineering, Inc. (SEI) manufactures a stern drive designed to replace Mercury Marine's MerCruiser®, Alpha One®, R, MR, Gen II and Bravo One® stern drives. MerCruiser®, Alpha One®, Gen II, R, MR and Bravo One® are trademarks of the Brunswick Corporation. SEI has no affiliation with the Brunswick Corporation. Consequently, any warranties governing products manufactured and/or sold by Brunswick Corporation will not apply to products manufactured and/or sold by SEI, or to products damaged due to the operation of an SEI product. Sterndrive Engineering, Inc. is not affiliated with Mercury®; Yamaha®; OMC® or their products. All reference to their trademarks and trade names are the property of the respective owners. Please include year and hp of unit you are replacing in the order notes!