Series 40 Ball Bearing Block - Triple - Swivel HeadFeatures: Low friction Acetal or Torlon bearing system Lightweight Cheek cut-outs for easy bearing maintenance Features a swivel shackle head for full 360 rotation Sheaves running on Acetal or Torlon ball bearings provide high performance low friction. The 2-stage ball bearing system provides consistent performance over the full load range.Applications: Mainsheet Halyard Vang Spinnaker control lines on off-the-beach catamarans, one design classes and sportsboats up to 8m (26ft) Materials: Acetal ball bearings UV stabilised Acetal sheave Grade 316 stainless steel load strap and head fitting Impact and UV resistant, fiber reinforced Nylon cheeks Truck Freight: No Oversized: No