From the manufacturer

The RESCUE M pulley is designed for rescue and work-at-height professionals. High-strength and very high efficiency, it is built for intensive use and handling heavy loads.

Features

• Designed to handle heavy loads and for intensive use:
  • Large-diameter sheave mounted on sealed ball bearings provides very high efficiency
  • Large attachment holes fit up to two carabiners for ease of use
  • Specific side plate design protects the rope path
    
    
• Moving side plates make it quick and easy to install
  
  
• Available in two colors: Yellow or black

Specifications