Mercury - Flo-Torq II Solid Propeller Hub Kit Performance Prop System Stainless Steel 835258K1. Overview. The Mercury 835258K1 Flo-Torq II Solid Hub Kit is built for high-performance boating and racing applications where reliability and precision matter most. Designed for use with Chopper, Cleaver, Lightning ET, Pro ET, and older Bravo One (with MerCruiser logo) propellers, this solid hub system ensures maximum power transfer and drivetrain protection. Every piece is engineered by Mercury Marine