Description: High Strength Forged Aluminum Magnesium Alloy, Super alloy body can bear up to 35 KN force Surface Anodized Oxidation, lightweight and durable, For Use with Ropes From 8 to 16 mm, Fits perfectly with double 8.1 mm ropes up to 13 mm single lines. Modern 8 Design for Smooth Handling, To reduce twisting of the ropes and formation of a lark's head knot Perfect for the Rock Climber or Search and Rescue professional Specification: Material: Aluminum Magnesium Alloy Size: Approx. 14x7.2cm / 5.5 x 2.8 inch Color: Blue Weight: 10 oz Package Includes: 2 Pieces Descender