The D5 Descender is designed for use on 1/2" (12.7mm) rope. The D5 is compliant with NFPA G ANSI Z359 and EN 12841. The D5 is a double-stop device with an auto-lock function. It is activated when the handle is released. The panic-brake function is not overly sensitive in normal use. The D5 also has a double-locking safety mechanism.  The side plates are designed so the plates cannot be rotated open, while in use. The D5 is great for working at height or any rescue or belay situation. The working load limit is 500lbs (240kg), suitable for 2 people.