Harken's 27 mm Midrange CB (Captive Ball) Track is made of tough 6061-T6 aluminum that is Hardcote-anodized black with Teflon impregnation for durability and easy bearing movement. It comes in both low- and high-beam configurations.Use standard low-beam track when it is supported at each fastener hole.Use this high-beam track when it must span a cockpit or other unsupported area. Refer to the 27 mm High-Beam Track Spanning Chart on our website for details. The high-beam track has an internal channel for mounting bolts that are held by rectangular slides (washers). Fasteners are not included. The sliding mounting bolts allow this track to be easily retro-fitted to an existing hole pattern, if necessary. High beam track is not available with pinstop holes. Maximum mainsail area for 27 mm track ranges from 14.9 m (160 ft) for multi-hulls with mid-boom sheeting using standard cars, to 32.5 m (350 ft) for lightweight mono-hulls with end boom sheeting When end controls are not used, add HAR #E2700 or #1523 endstops to absorb shock loads (sold separately) When end controls assemblies are used, trim caps can be used to finish the track ends Fasteners: 1/4"HH Can be bent to your specifications, please call for details Minimum bend radius for both Low- and High-Beam R27 Track: 2.44m (8ft) for standard/short cars; 2.73m (9 ft) for HL/long cars Note: Due to its length, track over 3.5m (9 ft) in length must be shipped via truck or air freight