Mercury 43-880707A03 Reverse Pinion Gear Set for Verado 350SCi-See Details
Because it's OEM, it's designed precisely for the gear housings / prop shafts specified (e.g. 350SCi Verado), which reduces risk of misfit or gear wear if used correctly. 350SCi Verado - 1B716557 THRU 2B143542.