The Herm Sprenger 2.5 mm short link chrome plated steel choke chain collar is the preferred choke collar for training. The high quality German machining and short link allow this collar to slip easily so that a correction can be quick and then released, making it an effective training tool. The 2.5 mm is considered a medium weight and useful for any biddable dog.
These collars are available in 6 different sizes. When ordering a collar, choose one that is at least 3-4 inches longer than your dog's true neck size. So, if your dog's neck is 15 inches around, order an 18 inch collar. If its neck is 18 inches around, order a 22 inch collar. (It's better to be a little long than too short.) You can also measure around the dogs head at the largest point and add 2". The chain is measured from the end of the ring to the end of the ring, not the length of the actual chain.
