This is a Type 2 braking device used for abseiling (rappelling) and belaying without a function to adjust the friction. Fabricated from an Aluminum alloy used for manufacturing aircraft s wings. Suitable for both single and double rope function. Optimum rope thickness: Dynamic single rope- 9.5-11.5mm, double rope: 8.5-9.5mm Static rope: 8.5-11.5mm. Weighs only 108 grams. Individually tested before shipping. Hot Forged Aluminum construction. Strength Rating: 25kN. Weight: 0.40lbs. Size: 4.8 x 3inches. Warning: Do Not use this product without proper training or supervision. If used incorrectly this product may lead to injuries or death! Read the enclosed instructions carefully before using this product.