A crack or embedder is a piece of metal used to climb through fissures, holes or ditches in the rock as an anchor, which allows establishing a belay point, ascent or installing meetings in the middle of the wall.[1]​ The main characteristic of crackers is that they fit into the rock without the need to be hammered due to their different mechanisms depending on the type, these are mainly divided into 2 groups: the "mechanical" ones, which are distinguish, and "passive."

Friends

Nowadays this type of embedding is essential in climbing. It is a cam expansion system, generally used in cracks of different sizes. There are two types:

Camless mechanical crackers

There are many types of these embedders, the most common are:

Passive fissures

This type is especially characterized by not having any mechanism, since they are pieces of metal with shapes capable of being embedded in fissures or holes, which are attached to a cord "or rope" where it is possible to place a carabiner "Carabiner (climbing)") to secure the rope.

Unlockers

They are tools used to extract fissures more easily when they are very wedged. There are several types, but they are generally long and have a small hook to be used to pull, push or move the pieces.