A water gun (or water pistol or squirt gun) is a type of toy designed to shoot water. It works on the same principle as a spray bottle. The body of the toy is essentially a container for water, and the "trigger" is attached to a pump which squirts water out of a tiny hole at the "muzzle." In the U.S. and Canada, for several years, import regulations and domestic laws have required squirt guns to be made of clear or tinted transparent plastic. This is to make them harder to mistake for actual firearms.
Variations of the design include using compressed air, rubber chambers or hydraulic pressure to propel the water, as in a Super Soaker, or an electric pump powered by batteries. It is debatable whether the higher-powered ones ought to be called "squirt guns", since "squirting" seems to imply a weak trigger-powered soaker.
