A lead has to be chosen in accordance with the size of the dog and its owner's aims (taking the dog for a walk, training, behavior correction, etc.). Small and medium-sized dogs will feel great with roulette-lead. This option is the most useful to take your dog for a walk in an urban environment. It is recommended to buy a lead made of durable materials, if you own a big dog. It is called "training lead" and can't be used constantly, but it is still a good idea to walk a big dog in an urban environment or for the cases when you need to use public transport.
There are chain-like leads that would perfectly fit short walks and photo sessions. It is not a good idea to use this kind of leads constantly – it is hard to pull and the fur of your pet can stuck between the chain links, causing a significant discomfort. If you want to take your pet to exhibition, you can use a show lead, the main purpose of which is to make your pet look more interesting.
More answers