A cold war era Secomak hand cranked air raid siren.

Type 447, designed and manufactured by Secomak during WWII and the Cold War.

Secomak (Service Electric Company of Stanmore, Middlesex). 

The sound box can be removed and stored between the legs of the the frame when not in use. See diagram.

Height: 82.5 cm.

Width: 35 cm.

Depth: 47 cm.

For a similar Secomak type 447 see the collection of the Imperial War Museum, London: Catalogue number FEQ 879.