pens but these contain an anvil where the explosive cap is placed, then a spring-loaded lever is pulled back and held in place by the cap of the pen. The pen is then ready to leave around or given to another person as a practical joke. When an unsuspecting person pulls the cap of the pen off, the spring drives the lever against the explosive cap for a surprise bang. Tri-ang Railways in the UK utilised caps in some of their OO gauge range of model rolling stock and accessories for toy play effect in the 1960s such as an exploding box car, a detonating rocket on their carrier transporter and an exploding fog signal accessory to mimic the effect of track detonators. See also Air gun Airsoft gun Modelguns (Japan) Paintball gun Toy gun References External resources Skooldays Discusses why cap guns might have first been manufactured. Toy weapons