Rock Exotica Omni-Block 2.0 Double

The Rock Exotica Omni-Block 2.0 double is a two-sheave pulley with Rock Exotica's swiveling Omni-Block design, making it a natural fit for compact mechanical advantage systems. Arborists use it to tension lines, lift hung-up wood a few inches, and build tidy haul setups.

Building mechanical advantage

Two sheaves let you build a 4:1 or 5:1 with a pair of pulleys, which is enough to tension a speedline, take slack out of a pull line, or lift a hung limb off a roof. The swivel lets the pulley line up with the load so ropes do not twist around each other, a common headache with fixed double pulleys.

Mechanical advantage multiplies force, which also means it can overload an anchor or rope without anyone feeling it. Keep the system within the rating of the weakest component and check Rock Exotica's published ratings for this pulley.

Because the side plates open, you can load the pulley onto a rope that is already rigged, which saves time when you need to add a system partway through a job without untying anything.

Care and inspection

Check the swivel for smooth rotation, spin each sheave, and look for cracks or wear on the side plates and attachment point. Keep it clear of grit and sap. See more pulleys in our rigging pulleys section.

Rigging forces are dynamic and can be several times the weight of the piece. Follow the manufacturer's ratings and ANSI Z133, inspect every component before the job, and keep rigging work to trained crews.