What is the primary function of pressure washer fittings?

Pressure washer fittings are used to direct and control the spray of high-pressured water. Attached to the spray wand at the end of a washer's hose, they include the nozzle and, on some models of washers, a coupling collar to allow nozzle changes.

Smaller electric pressure washers with lower water pressure usually have a single nozzle, which can be adjusted to aim the water stream in a triangular fan pattern. Gas-powered pressure washers for heavy-duty work come with multiple nozzles that can be swapped out for different kinds of jobs, for example a wide spray when detergents are included in the water or a narrow, penetrating spray to focus on deep stains.