All Neewa ® products are made of high-quality materials. The leashes, collars and harnesses are made of exclusive high-strength polypropylene to maintain strength and durability. Polypropylene is the most commonly used material in (dog) sports because it is hypoallergenic, light (it is a fiber with the lowest specific weight on the market), it does not shrink and it dries quickly because it does not absorb liquid. In addition, it is also 100% recyclable. All metal and plastic parts are also made of materials with a high resistance to cracks and extreme temperatures/weather conditions. This harness is ideal for walking dogs, not for pulling dogs.   Sizes Neewa Running Harness Size Neck Chest size