This is a set of 3 mini pressure sprayers, it can be used with most types of plastic drink bottles, fill the bottles with water, plant food, insecticide or a cleaning product, pump the plunger to build up the pressure and then press the trigger and you get a spray of water. The spray can be regulated from a fine mist to a single jet. It works with the 550ml, 1L, 1.5L, 2L and 3L bottles, on the shorter bottles you will need to cut the pipe to the correct length.