It is a device that is used above all strange to be able to go up or go by fixed ropes, to be able to hoist loads and to rescue maneuvers.
Nowadays there are several types of ascenders, but almost all base their operation on a toothed beam that presses the rope
The best known are the hand-held or "jumars" ascenders, of which there are for right or left hand. There are also chest ascenders to complement them with one hand, the Joint or "Duck" that is for self-insured abseiling, freights with self-locking and mini devices for emergencies and autorescat ... All work with a cam pressure that presses the Rope and almost all have teeth to improve the retention of the rope. The most successful models are those that are more comfortable to handle and those that have small details that make them more interesting: Ansa luminescent to be seen in the dark, water evacuation system, gel or mud ... etc.
The use of ascenders is for climbers on expeditions, for advanced climbers who practice the climbing of large walls and use them to climb by fixed ropes and to be able to hoist their duffels. They are also used as security features for autorrescat by climbers and mountaineers.
Other habitual uses: For professional use of rescue groups - for vertical works and industrial use - For caving and canyoning.