With so many dog training aids on the market, it is hard to find good advice on what collar to use. The three main types of collar are solid (traditional collar), half check or full check.
Full check chains are generally frowned upon in dog training clubs as they are often used wrong and can be damaging. Dont get me wrong, they are good if used correctly, but are often not. I certainly would not advise using one without having proper instruction first.
The general view from dog training clubs is to use a half check collar. This is a combination between a standard material collar and a check chain. It will allow the handler to check the dog to correct errors. The dog will respond to the sound as well as the slight tightening, but it will never tighten too much to choke the dog even if used incorrectly.
In addition to the collars listed above, im sure most of you will have heard of a halti collar. This is a material collar which fits around the head and nose. When the lead is pulled the halti tightens around the nose causing the direction of the head to be pulled to the side. The benefit of this is that the dogs attention is distracted away from what ever you didnt want them to be fixed on.
As well as training collars there is a massive range of other collars available from the basic and cheap to full on designer items, the cost can almost be limitless if you have the money.