The Freedom No-Pull Harness design minimizes or eliminates pulling, neck strain, and the chance of escape. The Freedom Harness is recommended by trainers as the 'ultimate in flexibility, control, and training.' Vets love the harness because it is designed to walk from the back of the dog keeping their spinal cords in alignment. Adoption groups love it because of its ease of use. Comfortable and durable! The Freedom harness has a soft Swiss velvet lining on the strap that goes behind the legs to help prevent rubbing, chaffing and sores that sometimes can be seen with other harness designs. All of the edges of the webbing are turned out to keep them from irritating your dog's skin. This well made harness will stand up to daily use by even the strongest dogs! Multi-functional: The harness can be used for discouraging pulling when attached to the front or for exercise when attached to the back. The double ended leash (included) can be attached to both the front and back of the harness or just the front or the back. Test it to see which works best for you and your dog! Industry leading lifetime chewing warranty: The manufacturer will replace up to two chewed straps for free, no questions asked, for just the cost of shipping. Reduces pulling! The patented action loop sits at the back of the dog between the shoulders allowing your dog to walk in a straight line without twisting or straining, while discouraging pulling by gently tightening around the chest. SIZING: Use a tape measure and measure the circumference of your dog's chest by placing the tape measure all the way around the chest (rib cage), behind the front legs. The tape measure should be not pulled too tight, but not loose. 5/8' XSMALL: 14'-20' chest, 13-21 lbs; 5/8' SMALL: 18'-24' chest, 18-35 lbs; 5/8' MEDIUM: 22'-28' chest, 30-50 lbs; 1' MEDIUM; 22'-28' chest, 30-50 lbs; 1' LARGE: 26'-32' chest, 45-80 lbs; 1' XLARGE: 30'-38' chest, 75-135 lbs; 1' XXLARGE: 36'-44' chest, 125-200 lbs.