The Halti OptiFit is a dog headcollar designed to help prevent dogs from pulling on the Lead. The Halti OptiFit headcollar, unlike other dog headcollars, is designed for dogs with unique nose and head sizes and can be adjusted to fit each dog's optimal fit without slipping or sliding. For dogs prone to pulling, the OptiFit Headcollar helps retrain dogs to walk normally and comfortably on the Lead without pulling. Available in three different sizes, the Halti OptiFit is great for small, medium and large dogs who pull on the Lead, and pet parents who are looking for a comfortable solution. Halti products are better together! The Halti OptiFit Headcollar works best when used with the Halti Training Lead with multiple connection points for optimal steering and control.Box Contains1 x HALTI OptiFit Medium, Training DVD, Written Guide, HALTI Link