HAAS develop specialist ascent Tree Climbing equipment. They are well know for the Velox system.
The HAAS Velox Foot Ascender, works as part of the HAAS system. It adds 18 inches of bungee, giving total 30 inches of travel. It gives a smooth ascent, with no set up required. The double tube system, is contained within the unit. Suitable to be used by different people, one-size-fits-all.