The Champion ST15 Third Spray 15' is for use on all 17, 18 and 19 Champion sprinklers. They are crafted from high quality Brass. They feature adjustable flow and radius and can match precipitation rates regardless of flow or radius. Champion irrigation has been in business for over 75 years. They manufacture high quality brass valves, couplers and sprinkler heads. They remain viable due to their durable line of products they consistently serve up to their customers.