The main use of a pear-shaped or HMS karabiner is to allow the use of an Italian hitch for belaying, occasional or emergency abseiling, and creating releasable anchors. It can also be used to create a single hauling point for rescues, especially connected to a bowline on the bight (or similar) knot. These are the pear-shaped karabiners that we sell:
Petzl Attache This is our lightest alloy pear-shaped karabiner, suitable for emergency use with an Italian hitch. It works best with softer or thinner ropes due to its smaller internal diameter. It’s also useful if you need to carry several things at once such as a pulley and a knife. Available in screwgate only.
Petzl William This is our larger alloy pear-shaped karabiner, available in screwgate or triact. It has a larger internal capacity, which means you can more easily reverse direction of an Italian hitch by turning the hitch over within the krab, even on thicker or stiffer rope. If you know that your rope falls into this category, you might choose the larger krab for this reason. It’s more suitable than the Attache for rigging a releasable abseil, for example for canyoning.
Edelrid HMS Bulletproof Screw If you’re in need of a bulletproof screw, we have absolutely no comment! This is a similar size to the William, but it has a steel insert over the main “wear” area. We would expect this to last longer than a pure alloy HMS (e.g. for instructional work) without the weight penalty of an entirely steel krab.
All these karabiners are H-profile construction for a good strength-to-weight ratio and have a keylock profile, i.e. a smooth nose to facilitate clipping and unclipping.