All Dogtra collars are made with surgical stainless steel and antimicrobial protection (straps), for a clean, odor fighting, long lasting product. These collars have great features, like non-stimulating pagers, a momentary vibration that warns your dog before a shock is enacted, and constant stimulation to train your dog to obey your commands.Dog behavior modification can be difficult, but with the YS500 fully waterproof low to high power collars, they make the adaption smooth and easy for your beloved companion. For medium to large sized dogs this collar and method of training is the best way to teach your dog not to bark, while allowing them the freedom of exploration and fun, ensuring the best relationship between you and your dog.