The Rainbird 15HC1 Adjustable Pattern Nozzle distributes water evenly regardless of pattern and is compatible with other Rain Bird Matched Flow Rate nozzles and 1804, SP40, SP25 and A17 spray heads. The Adjustable Pattern Nozzle has an adjustable flow and radius with a stainless steel adjustment screw. Two nozzles and filter screens are included. The 15HC1 Nozzle has a half circle spray pattern.