The Petzl OK Screw-Lock Aluminum Carabiner is lightweight and has an oval shape that allows optimal loading of devices with a wide cross section, such as pulleys, rope clamps, and mobile fall arresters. Its fluid interior design and Keylock system facilitate handling. It may be used with a CAPTIV positioning bar to favor loading of the carabiner along the major axis, to keep it integrated with the device, and to limit the risk of it flipping. The manual screw-lock with red band provides a visual warning when the carabiner is unlocked