UIAA Certified Auto Locking Climbing Carabiner Clips 25KN Heavy Duty Large Locking Carabiner Clips for Rock/Ice Climbing Rappelling D Shaped 3.93 Inch, Large Size, BlackQUICK AUTOMATIC LOCKING It's incredibly straightforward to use, allowing you to effortlessly manipulate this carabiner and loop using just one hand. Simply twist the barrel and push the spring to activate it,automatic re locking when you release the pressure. MATERIAL The climbing carabiner is made of lightweight 7075 aviation aluminum, which is not only lightweight but also strong. The net weight of each product is only 2. 01 ounces, making it