Star Mark Pro-Training Dog CollarOur Star Mark Pro-Training Dog Collar helps you control even the most stubborn dog. The pronged, linked design is gentle but effective in enforcing pack leadership. Boasting the appearance of a flat collar, this training collar offers custom sizing with the ability to add or remove links, much like a watch band. Constructed of high strength polymer for durability, this collar helps prevent pulling and lunging behavior. Additionally, Star Mark offers a free online training guide with step-by-step instructions.