One tether to secure your dog to your car's seatbelt is already included with each of Kurgo's Tru-Fit Smart Harnesses, Go-Tech Adventure Harnesses, and Tru-Fit Car Safety Harnesses. However, after a number of customer requests, Kurgo has made extra tethers available for sale separately‚ perfect for the dog owner with more than one vehicle who wants to leave the loops in place. Recommended for use with a driving harness.