Mercury - Flo-Torq SSR Propeller Hub Kit Soft-Shift Series Rubber & Composite 8M0150152. Overview. If you've spent enough time around docks or ramps, you know the unmistakable sound of a prop shifting into gear - that sharp clunk that makes everyone glance over. When you switch to the Flo-Torq SSR Propeller Hub Kit 8M0150152, that noise all but disappears. It's the kind of upgrade you feel instantly, not because it's flashy, but because it makes the whole boat settle into a smoother rhythm. Whet