Seems like a rather elementry question, but I see so many problems with the main shut off valves most people have used, thought I'd ask what other guy's use... Most systems here are on wells and do not have double checks or backflow preventers. There is usually a main shut off valve in a round box that's 2 to 4 feet down. Many have went to the glue-in plastic ball valves with the red handle, they seem to work well but if someone breaks off the ears on the handle you are boned... The other valves are usually brass threaded gate valves, they are pretty unrelieable, either they won't close tight, the stem leaks, or the handle rusts and comes off. Brass ball valves work the best, but the long handles on those have to be either bent or cut to fit into a 4" pipe. Many Iv'e seen the handle was galvinized steel and in a few years the handle has rusted and dosn't work right too. So what do the pro's use? BTW, this is a 1" or 1 1/4" valve, less than 20 gpm. Would only be turned off for winter then back on again for spring.