This signal is handheld and initiated by a friction fuze that has no delay.
Its main tube consists of a firm but thin cardboard tube held in a thin metal tube base.
Bottom of the metal tube is threaded and held shut with an unpainted alumin ium cap.
Under this cap the pull cord and ring are situated.

See this small internet film on the
use of the ROS serie.

Length : 206mm
Diameter : 41mm

Photos thanks to Jarda.




Photos below provided by Jarda Mattás.