A long line is essentially a 10- to 50-foot leash or length of material with a loop handle on one end and a snap or clip that attaches to a dog’s collar on the other––much like a normal leash, but longer. The material is generally nylon but can also be rope or, in some rare cases, chain. When using a long line, the dog should always be desensitized to it before any actual dog training can be done with it. The idea behind using a long line during instruction is to have it there for safety but to give the dog the illusion that she is "off leash" and can go anywhere she would like. The long line is a safety measure that a dog trainer uses when introducing distance and distraction to a trained dog who already comprehends a cue. It also has many other uses, including safely working on the “come” cue at a park. Your trainer will likely introduce this training tool during the training sessions. Make sure to follow all of the trainer’s instructions, especially for desensitizing your dog to the long line. This usually involves allowing your dog to drag it around the house for 20 to 30 minutes a day. Also, consult your trainer regarding usage of the long line. It is meant to be used during animal training and not as a tether for tying your dog up in the yard.