There are three types of signal rifle grenades; smoke ground streamer, illumination parachute and illumination cluster. The smoke streamers bodies are unpainted metal with black marking and a color band around the mouth of the rifle grenade indicating the color of the smoke. The canister ejects 6 discs with a smoke compound in them. The discs ignite emitting the smoke. The illum parachute style body also has an unpainted body with black marking. The closing cap on the rifle grenade is painted the color of the signal and has raised lettering for night identification. The illum cluster consists of five free falling stars that burn for 4-10sec.. The bodies are unpainted with black markings and marked with color on the closing cap as well as raised letters like the illum parachute style.
ILLUM PARACHUTE
nomenclature
raised letters
illum color
M17a1
WP
White parachute
M19a1,a2
GP
Green parachute
M21a1
AP
Amber parachute
M51a1
RP
Red parachute
ILLUM CLUSTER SMOKE STREAMER
nomenclature
raised letters
color star
M18a1,a2
WS
White star
m20a1
GS
Green star
m22a1
AS
Amber star
m52a1,a2
RS
Red star
nomenclature
color cap
smoke color
??
Green
Green
??
Red
Red
??
Yellow
Yellow