Petzl William Carabiner - Large, Pear-Shaped Locking Carabiner for Belay Stations - Screw-Lock Review (2026)

What the William is designed to do

Petzl's William is a lightweight, large capacity asymmetrical carabiner built primarily for belay stations and anchor building where a climber needs to connect several items at once, such as multiple rope strands, slings or an anchor cordelette. Petzl describes it as having an H shaped cross section aimed at giving an optimal strength to weight ratio while also protecting the strength markings stamped on the carabiner from abrasion over time. This screw-lock version uses a manual gate sleeve, and Petzl also sells the same William shape with automatic TRIACT-LOCK or BALL-LOCK gates for climbers who prefer a self locking mechanism instead of manually screwing a sleeve shut.

Strength and weight specs

According to Petzl's published specifications, the screw-lock William weighs about 85 grams and carries a major axis strength of 27 kilonewtons, a minor axis strength of 8 kilonewtons and an open gate strength of 8 kilonewtons, figures that comfortably clear the minimum requirements for a climbing locking carabiner. The pear, or HMS, shape is wider than a standard D shaped locker, which is what allows it to comfortably fit a Munter hitch, several rope strands, or a cluster of slings without everything bunching up against the spine. That extra room at the wide end is the core design trade-off of the whole HMS carabiner category.

Using it at multi pitch belays

At a hanging belay or a busy anchor station, the William's large pear shape lets a climber clip in the rope, a cordelette and a belay device all to the same carabiner without everything fighting for space, and its size makes it a natural choice for building a Munter hitch when a mechanical belay device is not on hand or has been dropped. Because it uses a manual screw-lock gate, standard practice applies, visually and physically checking that the sleeve is fully closed before weighting the anchor, and rechecking periodically during a long belay since a screwgate can work loose with repeated handling. Climbers commonly carry one or two of these dedicated to anchor building rather than clipping it into general rack use.

Trade-offs of the large size

The same roominess that makes the William great for holding multiple items at an anchor can make it feel loose or oversized for a single compact device like a GRIGRI, where a narrower dedicated belay carabiner such as Black Diamond's RockLock may sit more snugly. The larger size and pear shape also add weight to a rack compared with a small D shaped locker, which is worth factoring in for climbers counting grams on long multi pitch days where several lockers may be carried. Against the RockLock specifically, the William edges it out slightly on major axis strength, 27 kilonewtons versus 24, though the practical difference at typical climbing loads is minor.

Who should buy it

The William suits multi pitch climbers, guides and anyone building anchors that need to hold several items or a Munter hitch at one connection point, and it is a natural pick as a dedicated anchor building carabiner alongside a smaller locker for the belay device itself. Climbers who want one carabiner to snugly fit a GRIGRI or other compact belay device may prefer a mid sized HMS locker like the RockLock instead. Those who dislike manually checking a screwgate sleeve can look at the same William shape in Petzl's TRIACT-LOCK or BALL-LOCK auto locking versions for a similar large capacity with self closing gates.

Frequently asked questions