This double pulley is designed for cable or rope Tyroleans with an integrated Petzl Vertigo carabiner built-in. It is ideal to be used in forest adventure parks or your own home-made zip-lines. The Trac is definitely put in with one hand, and the aligned sheaves and sealed ball bearings will give nice performance with minimal friction and most potency. 1/2″ capability. Now not designed to be used in rigging zip-lines. (See our speed line kit to be used with branches and logs.)WLL 450 lb. Breaking Strength 4,500 lb.