During our testing, both units we tested slipped under bodyweight. See video below From Ocun: This is one of the safest ways to self-belay at the anchor, and it’s refreshingly easy to use. The integrated brake lets you fine-tune the length smoothly and precisely, so you’re not fighting your gear when it matters. Adjustment range runs from 20 to 100 cm, giving you plenty of flexibility for different anchor setups. The TWIN version adds a short secondary arm that makes rappelling more comfortable and less fiddly. A rubber carabiner fix keeps the carabiner locked in the correct orientation, so everything stays exactly where you want it—no twisting, no surprises. The safest sling/lanyard for self belay situation Shorter arm for more comfortable rappelling Made from durable dynamic rope Fall impact factor 2 absorption Rubber carabiner fix for proper carabiner fixation Integrated brake for optimal length adjustment Instructions for use.