This is the Replacement Lock Nut Set from OS Engines. / / FEATURES: Durbable steel construction. / Prevents the propeller from flying off even if the propeller / should slip or loosen due to detonation or knocking on / the large 2 or 4 stroke engines. / Replacement parts suitable for the BGX-1 3500-RN engine. / / INCLUDES: 1 metal propeller washer / 1 metal hex lock nut (sandwiched between prop washer and / expansion bolt) / 1 metal hex expansion bolt (installed last inside the lock nut) / / / 4-4-94 KrH