Each system has a set number of "zones" that the water cycles through. As the water passes through the actuator, it turns a series of gears that allows the high pressure water to escape through one zone at a time. The more common valves use 5 or 6 zones however, there are systems that use 2, 3, 4, 8, 9, or 12 zones as well. Once the zone of heads is activated, the heads stay popped up for approximately thirty seconds up to a full minute (depending on the system). Once they retract into the pool floor, the heads rotate slightly to make sure they face a new direction the next time they are activated.