This orbit 37217D extension adapter converts water sprinkler heads from a 1/2-inch to 3/4-inch threaded inlet. This male-threaded poly extension adapter is easy to connect an in ground sprinkler system pipe to a lawn sprinkler head. Durable plastic construction ensures that this Orbit riser adapter will have long-lasting performance. If you have a do-it-yourself sprinkler system or an automatic watering system that needs this conversion, this orbit 37217D extension adapter is the ideal adapter for you. Features and Benefits: Converts ?-inch garden sprinkler heads to have a ?-inch inlet, Sturdy plastic construction ensures long life, Used to connect lawn sprinkler heads to below-ground sprinkler pipes, Not for use under continuous pressure.