Not sure exact age , but we had these in use in our shop premises prior to 1974

Used condition , but in full working order. There are some tarnish marks , particularly on the galvanised rear plate ( see photos} plus  normal use/ surface marks you would expect for its age . Item has been tested manually by depressing the bimetallic strip and also tested by holding a lighted match below strip to trigger alarm and works perfectly . No batteries included- uses standard D cell

Operates by a bimetallic strip

Cream outer 

Approx 6" /15cm x 2 3/4" /7cm 

Designed to wall hang - small keyhole hanging hole on rear plate.

" Autolarm" Manufactured by Brook Precision Engineers, Farnborough , Hants.

Thank you for your interest