Here's what other sites are saying:
Simple to use and ergonomic, the RESCUCENDER is an openable cam-loaded rope clamp designed for use in haul systems as a tractor or progress capture device.
- Summit Hut
Petzl Ascenders & Descenders Rescucender Rope Grab B50A.
Description of Petzl Rescuender Rope ClampIntended for moving on fixed ropes as a back-up belay, for hauling heavy loads, and as a progress capture device in hauling systems.FeaturesSlides easily up the rope and jams when the cam is loaded. Slides easily downwards if the cam is prevented from engaging. If overloaded or subjected to an impact force, the rope may slip through the device. Locking pin gives greater safety disconnection from the rope requires two separate actions.Certification - CE EN 567 Individually tested. For use on single rope from 9 to 13 mm in diameter.250 g
- US Outdoor Store
Built for heavy-duty and rescue work, the Rescucender's spring-loaded design helps prevent damage to rope under shock loading.