For the Alien Flier X2 or X3 Model Zip Line Trolley
Tough Steel Sheaves
Sealed Chrome Bearings
You can return your backyard zip line to its original super-fast performance in just minutes yourself by replacing your original sheaves and bearing with a new pair. These are the same tough steel sheaves and sealed chrome bearings we use in all our trolleys and kits. Replacing worn sheaves and bearings could not be any easier. Simply remove the bolts and locking nuts, insert a new pair, then replace the nuts and bolts. **for the X2 Zip Line Trolley**