ISC Offset Oval Quadlock Carabiner

The ISC offset oval Quadlock carabiner pairs its offset oval body with a four-action auto-locking gate. The extra action makes it harder for rope or branches to roll the gate open, which is why climbers pick it for key connections on their saddle.

Why a four-action gate

A standard triple-action gate opens with a slide, a twist and a push. A Quadlock adds one more step, so the gate is much less likely to be opened by a rope running across it or a limb catching it while you move through the tree. For connectors that hold you, many climbers think that extra margin is worth the small extra effort.

The offset oval shape gives good gate clearance while still letting rope and hardware sit naturally on the spine.

Common spots for a Quadlock are the bridge connection, the lanyard end and the connection to a friction device, where a gate rolling open would be serious. For gear that clips and unclips all day, some climbers keep a quicker triple-action carabiner instead.

Using it correctly

Practice the gate on the ground with your work gloves until it is second nature, especially if you are used to triple-action carabiners. Load it along the spine with the gate closed and locked, and keep it out of positions where it can be cross-loaded over an edge.

As life-support equipment, it should be used per ISC's instructions and ANSI Z133, inspected before each climb and retired after a big fall or any damage. See all auto-locking carabiners for more shapes.