Big enough for sows. Small enough for weaners. Easy to clean. Simple to operate. Cheap as can be. Simple push-button operation is trouble free, and leaves the bowl clear for easy removal of straw or dirt. Cast iron bowl with brass valve. Bowl opening 12cm x 15cm. Suitable 5 to 65 psi by adjustment of flow-control device in valve. (Use large orifice for low water pressure.)