The Harken 40mm Switch Battcar with CRX rollers, clear anodized. Harken's award-winning, patented Switch T-Track Battcar system halves the stack height of mainsails on large yachts by stacking cars side-by-side on top of the boom, making it much easier for crew to fit sail covers and connect or disconnect halyards. Cars are Hard Lube-anodized and UV-stabilized for durability.