I train GSD (GSDCW) puppies and we introduce the collar to them at 12 to 20 weeks. As the pup grows, there is a need to add "prongs" but also to keep a snug fit under the ears. We have seen some owners turn the collar inside out and slide it over their dogs head but it will actually be too loose. As we humans get older is gets a bit harder to squeeze the prongs under the neck so this ClicLock is exactly what is needed to insure a great fit. Great design and very safe and secure.
