The fitting is attached to the end of a watering pipe and has a body (3) in which there is a channel (4) through which the water flows. A pipe connector (7) is present at one end. The fitting also includes a sensor (8) which can be displaced along an axis parallel to the axis of the channel. The sensor is indirectly affected by the fluid pressure flowing through the channel. A cursor (9) is displaced along a graduated scale (10) which extends parallel to the longitudinal axis of the channel. A mechanical device (11) correlates the movement of the cursor as a function of the displacement of the sensor and of the channel cross section so as to indicate the instantaneous flow rate.
