SEI Mercury Four Stoke Replacement 2.33:1 20" Lower UnitNote for purchasing: You must verify your Gear Ratio. Call for application assistance if needed, and have your engine serial number ready when calling.Specifications: OE Part#: 9011J29; Length of Spline: 20"; Gear Ratio: 2.31:1 , 2.33:1; Item is subject to a 20% restocking fee (Boat Covers, Bimini Tops, Outdrives, Drop Ship Items and Special Order Parts)!**Year, Serial Number, and Horsepower are required to order. Please contact us with this information after you place your order otherwise processing will be delayed