CMI Micro Pulley 1/2″ Capacity & Moveable Cheek Plates Purple. This CMI micro pulley is one of our most popular climbing pulleys. Often used in knot tending applications and others. Features and specifications: Aluminum Cheek Plates and Sheave. Moveable cheek plates for easy insertion anywhere in a line. Capacity: 1/2″ Diameter Rope Tensile Strength: 7000 lbs. Sheave Diameter: 1.25″ Pulley Height: 2.50″ Manufacture: CMI