Tied Helix - ER Developed to produce a quick upshift and improved backshift for excellent throttle response, Dual-angle-option helix fine-tuning for changing conditions, ER helixes are for Ski-Doo and Polaris machines with engine reverse, Type F = full progressive; type .46 = .46 progressive, Helixes for TIED and TSS-04 clutches are NOT interchangeable.