Cap banger for an explosive joke

An explosive cap is placed inside and the spring loaded arm is pulled back and held in place by the hinged lid. If an object is placed on top of the banger, the lid cannot flip back. However, when the object is lifted the cap will go off.

Details

Size 40 x 20 x 7mm
Date Probably mid 20th century.
Key Phrases
Category
Ref no N2836