The Swiss army uses some grenades to simulate incoming fire. They were manufactured by HansHamberger AG.
Basically there are two groups:
Heulpetarden (“howling-petard”) which make a howling sound Knallpetarden (“bang-petard”) which make a bang
Each group has four types: -Without smoke (basic colour: black) With red smoke (basic colour: red) With yellow smoke (basic colour: yellow) With blue smoke (basic colour: blue) They are all cardboard constructions. The handle is empty and at the upper end of the head is a cap. Below the cap is a friction fuze (matchhead with a striker on a cardboard disc; 5 seconds delay).