The DMM Hitch Climber Combo includes the DMM Hitch Climber pulley, two symmetrical DMM Ultra O (oval) carabiners and one Whiptail 8 mm Ocean Polyester friction cord - 850 mm long, stitched eye-to-eye - this tree climbing system was designed by the Treemagineers and is used by most of New Zealand's leading tree climbers. Teufelberger Ocean Polyester is composed of a polyester/aramid sheath with a polyester core offering high abrasion and heat resistance and it's very 'grippy'. This second generation Ocean Polyester is made softer for easier knotting. Make a saving over buying each item individually - just add Teufelberger Tachyon and a TreeMOTION (also made by Teufelberger) and you are ready to climb.