ISC Offset D Supersafe Carabiner with Locking Pin

The ISC Offset D supersafe carabiner is an auto-locking connector with an extra locking pin that guards against accidental opening. The offset D shape opens wide and loads well.

Why an extra locking step

In tree work, carabiners rub against bark, ropes, and other hardware all day. A standard auto-locking gate can still be opened by a rope or branch twisting across it in the right direction. The ISC supersafe design adds a locking pin, so the gate needs an extra deliberate action before it opens.

The offset D shape puts the load close to the spine, where the carabiner is strongest, and gives a wide gate opening for clipping a bridge, a rope, or a thick eye. That makes it a good fit for saddle attachment points, lanyards, and other places where you want maximum security.

The trade-off is that it takes a bit more practice to open, especially with gloves or cold hands.

Use and inspection

Load the carabiner along its long axis, and do not let it cross-load against the gate. Check the markings and ISC's instructions for ratings and approved uses. Compare other options in auto-locking carabiners.

Before each climb, check that the gate opens smoothly, closes fully, and that the locking pin engages every time. Look for grooves, sharp edges, cracks, and corrosion, and retire the carabiner after a big fall or drop. Rinse grit out with fresh water and dry it well. Life-support gear must meet the applicable standard, follow ANSI Z133 and the manufacturer's instructions, and be inspected before every climb. Get trained before you rely on it.