DMM Perfect O Carabiner

The DMM Perfect O is a symmetrical oval carabiner, and that shape keeps pulleys, rope grabs, and ascenders centered instead of sliding toward the spine. Arborists use it wherever a device needs to sit square, such as on a hitch-tending pulley or a lanyard adjuster.

Why choose an oval

Most carabiners are D or pear shaped, which pulls the load toward the spine. That is fine for a rope, but a pulley or rope grab on a D carabiner can cock sideways. The Perfect O's symmetrical oval lets the device hang centered, so it runs smoothly and loads evenly.

That makes it a natural fit for pulleys below a friction hitch, for rope grabs on a lanyard, and for racking several pieces together. Compare other auto-locking carabiners if you need a larger pear shape for hitches.

Strength, use, and inspection

An oval carries less load on the major axis than a comparable D because the load is centered rather than near the spine. Check the strength markings on the gate and match the carabiner to the job; do not cross-load it or load it over an edge.

Inspect the gate, locking sleeve, and nose before every climb and retire any carabiner that has been dropped onto a hard surface from height, shows cracks or deep wear, or does not close and lock cleanly. Life-support gear must meet the applicable standard and the manufacturer's instructions, be inspected before every climb, and be used only by trained climbers working to ANSI Z133.