This is a British WW2 Air raid siren manufactured in London by Leach Electrical Ltd. It is in fully working condition and has two volume levels - loud and really loud.

The makers plate has the date 7 - 43, WD and the Broad Arrow marking.

This siren still has a lot of its original paint, some is missing on the handle side of the unit, but the rest is remarkably intact for such an old piece of equipment, see the pictures for more detail. The wooden handle has no cracks and has 90% of the paint intact.

The vents on the side open and close easily with a twist of the top handle, this is the mechanism that controls the volume.