Locking Carabiner,GOTD Pulley System Stainless Steel Carabiner Opener Outdoor Climbing Multi-Tool Survival Gear Size: 90mmX38mmX7mm/3.54"X1.50"X0.28" Material: High Tensile Stainless Steel Integrated karabiner pulley system specifically designed to be used with paracord. Use the Para-Pulley singularly for directional change and greatly reduce friction. Single pulley allows for lines up to 1/2" diameter. Offers 5 wrench openings 15/16", 9/16", 1/2", 7/16", 3/8", 5/16", 1/4" (bit driver).