Rain Bird introduced the AP model to its storied line of pop up impact rotors sometime in the 1980’s or 1990’s. Not to be mistaken with the SAM models that were introduced with a plastic case in the 1970’s, the 21AP is essentially an exact copy of the cast iron case, but executed in plastic. In this video, I talk about the sprinkler, my own failure to ascertain when it was introduced, how the internals could be replaced, and then I show it in operation. I hope you enjoy it, and thanks for watching!