O.S. Engines 45510100 Prop Locknut FS-120

This is a replacement locknut and washer set for the FS90 and 120surpass and / the 120 surpass w/o pump. . / / Features: This helps keep the propellor stay on the engine in the case of / backfire or detonation. / / The inner nut screws into the outer and locks it in place. / / / Includes: / 1- inner prop nut 5/16-24 thread / 1- outer prop nut 5/16-24 thread / 1- prop washer I.D. 12.5mm O.D. 32mm / gab4/5/94