SEI SE228 Mercury Counter-Rotation Lower Unit 1.85:1 25"The SEI 90-228-B25F SE228 is an aftermarket counter-rotation replacement lower unit for select 200275 HP 2.6L inline-six four-stroke Mercury outboards. Featuring a 1.85:1 gear ratio and 25-inch driveshaft configuration, it replaces OE number 880686T15.This item is subject to a 20% restocking fee.Year, serial number, and horsepower are required to process your order. Please contact us with this information after placing your order. Processing will be delayed until this information is received.Features Counter-rotation configuration; 1.85:1 gear ratio; 25-inch driveshaft configuration; 20-spline driveshaft; 15-spline propeller shaft; 4.88-inch torpedo diameter; Applications and Replacement ReferenceFor compatible 200275 HP Mercury 2.6L inline-six four-stroke outboards requiring this gearcase configuration. SEI part number: 90-228-B25F; OE replacement reference: 880686T15; Fitment and OrderingConfirm your exact engine application, serial number, original gearcase number, rotation, gear ratio, shaft configuration, and case diameter before ordering. Horsepower, gear ratio, and shaft length alone do not confirm compatibility.