A low-flow emitter includes a rotatable cap and a body. The rotatable cap has a threaded hole and a receiving chamber communicating with the threaded hole. The wall of the receiving chamber has plural grooves, which are annularly arranged in a spaced manner around the threaded hole. The body has a shaft. The shaft has an external thread and a flexible rib adjacent to the external thread and is connected to the rotatable cap by threaded connection between the external thread and the threaded hole such that the flexible rib is engaged in one of the grooves. When the rotatable cap is rotated to adjust the amount of water delivered by the low-flow emitter, the area of contact between the grooves of the rotatable cap and the flexible rib of the body stays unchanged, allowing the rotatable cap to produce a consistent feel to the operator.
