This is Harken's 22 mm low beam track for captive bearing cars with special 4" mounting hole spacing for replacing pre-existing travelers with 4" fastener spacing (e.g. Nicro Fico, etc.).22 mm Small Boat Captive Bearing (CB) Track is used on travelers, adjustable genoa leads and as mainsail mast track. It comes in low-beam or high-beam configurations. Use low-beam track when it can be supported at each fastener hole; high-beam track is appropriate when spanning a cockpit or other unsupported area. Maximum mainsail area for 22 mm track ranges from 7.5 m (80 ft) for multi-hulls with mid-boom sheeting and standard cars, to 18.6 m (200 ft) for mono-hulls with end boom sheeting and high load cars Hard anodized aluminum construction Fasteners: 5 mm (#10) Flat Head Splice link is used to align low-beam track during installation of multiple sections (eg mast track installation) Can be bent to your specifications, please call for details Min. bend radius for 2-7/8" cars: 1.07 m (42"); for 4-1/8" cars: 2.03 m (80") First fastener hole is 51 mm (2") from the end of the track Note: due to its length, track over 8 ft long must be shipped via truck or air freight