The HAAS (Haul Ass Ascent System) designed by Michael Frankhauser of Ohio, USA is the an extremely efficient way to enter a tree - it uses your large leg muscles for ascent on a single line, leaving your arms free to fend off branches and guide the way.
The HAAS requires an additional foot ascender to be worn on the opposite boot. Both 'toothed' cams on the ascenders are positioned below your connection point for added safety. The HAAS can be utilized in DbRT (Doubled Rope) and SRT (Single Rope Technique) tree climbing systems. Perfect for use with the Singing Tree Rope Wrench or Rock Exotica Unicender.
The 'Regular' HAAS puts the middle of the ascender 400 mm above the top of your foot the 'Long' HAAS puts the middle of the ascender 480 mm above the top of your foot. Keep in mind, your knee may not be in the middle of the range, so using your knee as a reference may not provide the best results. The measurements above should provide the best performance.