Petzl have just released detailed information about the new Zigzag mechanical prusik. Based on the very popular first version but with slight design changes, it is likely to be very popular with arborists.
The main changes include strengthened side plates and resigned attachment holes to help keep the karabiners loaded correctly on their major axis. The attachment hole at the rope end also now has a flexible elastomer ring that helps keep the karabiner orientated to its optimal working position (reducing the risk of poor positioning and the cantilever effect that occurred with the previous Zigzag). The harness end attachment ring has also been enlarged to reduce the risk of poor karabiner positioning and prevent the karabiner sleeves from snagging. Even with these changes, as with most devices, it is imperative that the user is vigilant about the karabiner positioning. Other minor changes includes extended side plates to help guide the rope in the sheave. They are also now flared to ensure smooth operation even if the rope rubs on the side plates.
– The changes above were tested and approved using the Petzl OK Triact (Triple action) and Am’D Triact Ball-Lock karabiners. Other karabiner models of similar shape may be used, but their compatibility must be verified by the