CMI Shackle Pulley

The CMI shackle pulley pairs a pulley with an attached shackle, so you can connect it to a sling or anchor without a separate carabiner. Arborists use it for redirects, small mechanical advantage setups and hitch tending where a clean attachment helps.

On the job

A shackle pulley lets you hang a pulley straight from a sling, ring or eye without stacking another carabiner, which keeps the system short and reduces cross-loading risk. That is useful for a quick redirect on a climbing line or for building a small mechanical advantage to tension a line.

Because the shackle stays with the pulley, it is one less piece to find when you set up. Keep it on a gear loop where you can reach it.

The shackle style also suits fixed points such as an eye on a sling, a ring on a friction saver or a tie-in on the truck. Keep in mind that a shackle takes a moment longer to open than a carabiner, so it fits best where the pulley stays put for the whole job rather than being moved every few minutes. For quick, frequent moves, many climbers still carry a carabiner pulley as well.

Inspection

Check that the shackle pin threads fully and stays secure, that the sheave spins freely and that the side plates are not bent. Look for grooves where rope runs and replace the pulley if it shows cracks or deformation.

Use it within CMI's rated loads and instructions. Any part of a life-support system must be used under ANSI Z133 practice and by trained climbers. Compare it with other models in micro pulleys.