When every gram counts, the Sender Twistlock Carabiner is the right choice for climbers who demand performance. This extra-lightweight and compact carabiner features a âD' shape for easy handling. The twist-lock closure allows quick automatic locking and can be operated with one hand. The keylock nose prevents any snagging when clipping and unclipping. One of the lightest and most compact twist lock carabiners on the market.