The Geyser Stop! Is an automatic shut-off valve for landscape sprinklers and risers. The Geyser Stop! attaches to an existing sprinkler system between the water supply line and the sprinkler head. When the sprinkler head or riser breaks away (due to some trauma for example: a vehicle, lawnmower, pedestrian, or bicyclist accidentally impacting the head), the valve is automatically activated and stops the flow of water at the broken head. Comprised of a tubular fitting equipped with an internally positioned stainless steal ball bearing, when the sprinkler or riser breaks, the water pressure causes the ball bearing to seat inside the valve, stopping the flow of water out of the system. This stoppage also provides the required backpressure to ensure proper function of the remaining operable sprinkler heads. www.nogeysers.com.