Petzl
Openable even when attached to the anchor, the SPIN L1 pulley is designed for maximum simplicity in setting up hauling or load deviation systems, and tyroleans. The large diameter sheave mounted on sealed ball bearings gives it excellent efficiency. The swivel facilitates handling, allowing the pulley to be oriented under load, and direct connection of carabiners, ropes or slings.
Triple-action opening of the moving side plate is quick and easy, even with gloves.
Installing the rope
The rope can be installed with the device connected to the anchor.