A masonry water-control structure built into a stone wall, with a large threaded screw wheel at the top driving a slatted timber gate up and down, iron strap reinforcement and a round grated outlet to one side. A short stepped ramp runs along the base.

The heavy stonework and hand-cranked mechanism suit a canal, mill-race, watermill or irrigation channel.

An atmospheric infrastructure piece for a rural diorama, a model-railroad waterway or a medieval-flavored tabletop board.