This 29 mm triple Carbo block has a 29 mm single attached to the becket. Use this block in a 7:1 purchase system with the 345 triple to relieve rig tension either overnight or to make taking a rig down easier. Used on VX-One, 49er, and 49er FX. It offers Carbo’s lightweight, strong, and reliable fiber-reinforced construction with free-running ball bearings.