Smart Leash and Smart Collar both have easy to clean technology that allows the leashes and collars to look new longer. They come in different sizes to fit most dogs. Collars are available in small, medium, large and extra large. Leashes are available in 1" and 3/4" widths and adjustable to fit most sized dogs. Both Smart Leash and Smart Collar are available in Red, Blue, Black, Pink, Green, Teal, Violet, Gray, Tan and Olive Drab.