Please bid with confidence. Since 1985, I have rebuilt and tested more brass impact sprinklers than anyone. Our customers have included many of the most prestigious golf courses, college and pro sports stadiums, farms, and ranches in the USA.  Now because of the internet our new and rebuilt sprinklers, as well as repair parts and rebuilding services, are available to everyone. Recently a couple of sellers have popped up on ebay offering rebuilt sprinklers. Please don't assume that all rebuilt sprinklers are rebuilt the same way and are of the same quality.  These other reconditioners are using high impact glass bead to clean the brass (like sand blasting); I can tell because back in the 80's I did the same thing( I don't care what they say yellow sprinklers = impact blasting). You end up with a nice looking, shiny brass sprinkler; however, I found that the glass bead removed small amounts of the brass which pitted the nipple and bearing. These pits held dirt, debris, and water deposits which did not allow the sprinkler to self flush, as it was designed to do.  The sprinkler ends up freezing up or grinding down the washers and the bearing. Glass beading not only does not clean the most important part of the sprinkler, the inside, it makes the sprinkler bearing less rebuildable the next time due to the damage.  I included a picture of brass nipples cleaned using my unique cleaning process that took years to perfect - glass smooth with no brass missing! If you buy a so-called "rebuilt" sprinkler from someone else and this spring you turn it on and, for whatever reason, it doesn't work, will they be there to help you? Do they have the inventory to replace it? I will. I do. Thanks, Frank