This connector will allow you to split the flow of water from one hose to two.  Each arm of the Y has its own cut-off valve that allows you to direct the flow of water.  With a quick-connect on one arm of the Y and a hose running off to the next sprinkler, it is possible to run multiple sprinklers in series--so long as the water pressure is high enough.  Just like an automatic, in-ground system, the sprinklers must be run in "zones" that have enough pressure to work all the sprinklers in the zone.