CMI Micropulley The CMI Micropulley is one of the most popular micropulleys in arborist climbing — and it's easy to see why. Versatile, lightweight, and built to handle real loads, it excels at slack tending, fairlead control, and general redirect applications. The swiveling side plates allow mid-line attachment without threading the rope, making rigging changes fast and efficient in the field. At just 0.15 lbs, the CMI Micropulley adds almost nothing to your kit weight while delivering a robust 31 kN MBS — one of the highest ratings in its class. Aluminum construction keeps it light without sacrificing strength. Specifications MBS: 31 kN (7,000 lbs) WLL: 6 kN (1,400 lbs) Compatible rope diameter: Up to 1/2" (13 mm) Weight: 0.15 lbs Side plates: Swiveling (opening for mid-line attachment) Material: Aluminum Manufacturer: CMI Corp (USA) Key Features Swiveling side plates for quick mid-line rope attachment Excellent for slack tending and fairlead control High MBS of 31 kN — one of the strongest in its class Ultra-lightweight at just 0.15 lbs Versatile multi-use design for climbing and rigging systems Frequently Asked Questions What is slack tending? Slack tending refers to managing excess rope in a climbing system to prevent it from tangling or catching. A micropulley like the CMI is often used as a fairlead — a guide that keeps the rope running in the right direction and prevents it from wrapping around gear. How does this compare to fixed-plate micropulleys? The swiveling side plates allow you to attach the CMI mid-line without threading the rope through, which is faster in the field. Fixed-plate options like the ISC Fixed Cheek Micropulley or Petzl Fixe Micropulley are more stable for rope wrench applications but require threading during setup.
