The Helios Bark-Mudder Easy Tension 3M Reflective Endurance 2-in-1 Adjustable Dog Leash and Harness is composed of 600D Oxford Nylon and Polyester. The Leash portion features Dual Rubberized easy tension cords location at the connector and by the handle bar for easier tension and features metallic swivel attachment and connector pieces that help prevent any leash tangling for a more convenient dog walking experience. The accented colored harness portion features Heavy-Duty Velcro enclosures with above protective Double-Adjustable Nylon straps with metallic buckle straps and surrounded 3M Reflective lining for added security. Get Outdoors with Helios Dog! Available in Multiple Colors and Sizes. SIZING MEASUREMENTS (INCHES): SMALL: Body: 6 Chest: 15 - 17.3 Neck: 15.7 - 18.1, LEASH 5 FT: MEDIUM: Body: 6.3 Chest: 18.9 - 22 Neck: 18.1 - 20.9, LEASH 5 FT: LARGE: Body: 7.1 Chest: 24.8 - 28 Neck: 22.8 - 25.6 LEASH: 5 FT.