System AA CB Typical Boat Size: Monohulls: length to 37 ft (11.3 m); mainsail area under 350 ft2 (33 m2) Multihulls: length to 30 ft (9.1 m); mainsail area under 275 ft2 (26 m2) The one-piece solid aluminum construction is lightweight and strong. The free-rolling ball bearing cars let you hoist and reef the main quickly on all points of sail. Cars are easily removed from the track by freeing the screwpin endstop and sliding them off. Stainless steel wire guides keep the balls captive when the car is off the track.