Rainbird 1800 Series Pop-Up Spray Head with Seal-A-Matic Without Nozzle, 12" 12 in. 1800 Series pop-up spray head with Seal-A-Matic check valve Designed for use with all Rain Bird plastic spray head nozzles Traps water in lateral pipes in elevation changes of up to 14 feet (4,2 m) and Overall length of sprinkler is 16, Pop-up portion 12 Reduces wear on system components by minimizing water hammer during start-up Prevents drainage from spray heads at lower elevations - Stops water waste