Oval-shaped carabiner for use with pulleys or ascendersThe Petzl OK Screw-Lock is a lightweight aluminum carabiner with a symmetrical oval shape that allows optimal loading of devices with a wide section, such as pulleys, ascenders and progress-capture pulleys. The screw-lock closure is an easy-to-open system, locking or not, according to the need of the user. The red band provides a visual warning when the carabiner is unlocked. This system is suitable for difficult environments where contaminants (mud, ice) could cause an automatic locking system to jam.