Medium flow sprinkler, rotating at full or part circle with slow return. Suitable for all types of travelling irrigators, can be used also for centre pivots and normal installations. An intermittent and adjustable jet-breaker working only on the return maximises the uniform distribution of rainfall over the irrigated area, including in the immediate vicinity of the sprinkler. Engineered to minimise vibrations and recoils that lead to overturning of trolleys or stands, providing greater safety to the user. Suitable for use on sloping terrain.