Hose attachment sprinkler devices
There are many types of tools that can be attached to a hose for watering the lawn. Each one has limitations and features that allow it to perform poorly or well, depending on how it is used.
Oscillating sprinklers operate by rotating left and right, back and forth, putting out streams of water high into the air. They can be adjusted to cover a large rectangular area, or smaller area that is half the size of the larger one. Some models also feature pulsating action or “center-top” delivery, which are mostly marketing gimmicks.

Impact sprinklers deliver water by rotating in a circular fashion, dispensing horizontally. They have a small screw or deflector which intentionally distorts the spray pattern to produce both large droplets and mist. Impact devices can be adjusted to water in a full circle, or any part of a circle, allowing them to be used on small lawns with odd shapes. Both impact and oscillating sprinklers can allow a substantial amount of water to drift off the lawn, especially if you water on a windy day.
The third common type of watering device that are attached to a hose is a rain train. This is a relatively larger unit which travels in a straight line over the lawn, directed by a fixed steering piece that is guided by the hose. Rain trains are the most efficient type, delivering large droplets of water close to the ground. They are moved through the lawn by large toothed drive wheels, designed to operate slowly along the length of hose. Though efficient, rain trains are limited to use on relatively flat, rectangular or square lawns.