SummaryThe relay pulsator described here has been found to give reliable and efficient operation both in laboratory tests and in field use. The air passages and ports can be designed to provide ample cross‐section to handle the air from at least two sets of teat cups without changing the shape of the pulsation curve, and also can provide the air path necessary for operation of releasers or as a master pulsator.The unit is very robust and can be washed by circulation washing procedures without any risk of damage. The low cost of manufacture and the ease of installation and maintenance are all features in its favou