Petzl Am'D Triact-Lock Carabiner

The Petzl Am'D Triact-Lock is the Petzl carabiner a lot of arborists reach for first: an asymmetric D-shaped aluminum locker with a three-action auto-locking gate. It is strong, light and sized to hold a hitch, a pulley or a lanyard eye without crowding.

A go-to Petzl climbing carabiner

The Am'D has been one of the most common Petzl climbing carabiners on tree saddles for years, and for good reason. The asymmetric D shape keeps the load close to the spine, where the carabiner is strongest, while leaving a wide opening at the gate end for rope, eyes and pulleys.

It handles split tail hitches, rope wrench tethers, lanyard eyes and rigging connections with equal ease. Many climbers run a matched set of them so every connection on the saddle behaves the same.

The aluminum frame keeps weight down, which matters once you have six or eight carabiners on a saddle. Over a full day of climbing, those ounces add up in your hips and legs, and lighter hardware is one of the easiest places to save weight without giving up strength.

How the Triact-Lock works

The Triact-Lock gate needs three movements to open: slide, twist and push. That makes it very hard for a branch or rope to open by accident, and the gate locks itself as soon as you let go. It takes a few climbs to make the motion automatic, but after that it is quick to use with gloves.

If you want a screw gate for semi-permanent connections, the Am'D Screw-Lock uses the same frame.

Loading and placement

Load the carabiner along its long axis with the gate closed and locked. Keep it from cross-loading against your bridge or another connector, and avoid letting the gate rest against bark or a limb where pressure could work it open.

For pulleys and hitch setups, check that the carabiner sits flat and the rope runs over the right part of the frame. A captive pin or rubber keeper can help hold orientation.

When you set up a rope wrench tether or a hitch on a split tail, make sure the Am'D sits so the rope runs over the wide end of the frame and the gate faces away from your body and the bridge. If it keeps flipping into a bad position, a rubber keeper or a captive-eye setup can hold it in place. Check orientation each time you rebuild your system.

Inspection

Check gate action every time you climb. It should close fully and lock on its own. Rinse out grit, look for rope grooves, and retire any carabiner that has taken a hard drop or shows cracks or corrosion. Life-support gear has to meet the applicable standard and the manufacturer's instructions, get inspected before every climb, and be used only by trained climbers.

Keep an eye on the gate sleeve in particular. Sap and sawdust can make a Triact-Lock sluggish, so it may not fully lock when you let go. Rinse it in warm water, dry it well and check that it snaps closed and locks on its own before the next climb.