Petzl TRAC pulley with VERTIGO WIRE P24AUB No-drop pulley for Tyrolean traverses. Specially designed for Ziplines. One Handed Operation The VERTIGO carabiner is attached to the TRAC pulley, making the unit drop-proof, and thus simplifying maneuvers. The clip-on, lockable cover with optimal shape makes it easy to connect the TRAC to a pulley lanyard Rugged construction: - use of single-row ball bearings optimizes lifespan - carabiner with proven durability and very easy to use WIRE-LOCK locking system - two supports for the progression carabiners allow them to be protected from cable wear - joining piece distributes contact points between the carabiner and the pulley to increase the longevity of the carabiner Easier for the operator: - clip-on, optimally shaped lockable cover makes it easy to connect the TRAC to a pulley lanyard