From the English "neckline" literally "neck line", this element is used to connect 2 dogs by their collars.
Often light and equipped with different sizes of snaps depending on the size of the dogs.
Do not forget that this element will "fuse" in the event of a violent impact, hence the use of small carabiners intended to break to avoid any risk of injury to dogs.
When there is "chewing" or line biting dog, the choice of cable instead of rope is essential.