Now you can get closer to the fish with the Troll Prop Saver. The unique Troll Prop Saver helps protect your prop from underwater hazards like stumps, rocks, and seaweed - places where fish may hide. The Prop Saver also prevents fishing line and downrigger cable from tangling around your prop during sharp turns. Increases thrust and steering efficiency. Made of high-impact 304 stainless steel. Fits most motors. Note: High speed and shallow water running are not advised. Troll Prop Saver Model # 4• Fits 9.9 hp to 15 hp outboard (not for Merc Bigfoot or Pro Kicker)• Also for use with 6 - 9.8 hp 4-stroke• Max. Prop Diameter: 10" Increases thrust and steering efficiency Fits 9.9 HP to 15 HP 10" max. prop diameter Troll Prop Saver, Model 4.