Polastorm
PolaStorm Nyloc Nut for Mercury & Mariner 40 Bigfoot + Outboards + Mercruiser Alpha One drives
Brass Nyloc Nut from PolaStorm to suit all Mercury / Mariner outboards with 4 1/4" and 4 3/4" gearcases.
Will fit Bigfoot model outboards from 40hp upwards and MerCruiser Alpha One Drives