Crafted from 3/8″ wide 100% nylon webbing that is machine-washable. Each nylon dog collar has an Acetyl side release closure and comes with a 2′, 3′, 4′, 5′, or 6′ matching leash. The leashes of the same material have a hand loop on one end and metal swivel snap hook collar attachment opposite to eliminate twisting. The 3/8″ collar and leash combo are not recommended for dogs with necks over 12 inches.