A windscreen wiper device comprising an elastic, elongated carrier element, as well as an elongated wiper blade of a flexible material, which windscreen wiper device comprises a connecting device for an oscillation wiper arm, wherein the oscillating arm is pivotally connected to the connecting device about a pivot axis near one end. A flow-actuated valve inside a fill tube regulates the flow through the fill tube. An indicator mounted to the proximal end of the shaft indicates the valve size corresponding to the outer dimension of the valve sizing portion. The turbine shaft and the generator shaft are connected to one another. 35% by weight as measured with a Karl Fischer moisture meter.