|Place of origin||Astronea|
|Used by||Astronean Armed Forces|
|Designer||Bavra Chemical Solutions|
|Manufacturer||ACC Defence Division|
|Length||600 mm (24 in)|
|Effective range||123 m (135 yd)|
|Filling weight||326 grams|
|1.5 second fuze|
The SK-55/90 is a non-lethal coloured smoke grenade designed for target identification and troop screening. It is designed to be cost effective and easy to deploy, usable in a variety of environments. Its 1.5 second fuze is sparked by pulling the safety pin and spool from the grenade, and smoke will begin to billow out for up to 85 seconds. It is available in a variety of colours, including white, orange, purple, blue, red and green. While not lethal, its chemical smoke is harmful if inhaled for any extended duration. Its ignited fuze also burns hot, which can cause burn injuries if picked up after being thrown. This heat also has a potential fire risk if deployed in especially arid bush lands.
The SK-55/90 features a standard fuze, pin and safety spool. Once the pin is pulled, the grenade is off safe, but not ignited. Ignition can only be achieved by removal of the safety spool, either by squeezing or by inertia of throwing. This prevents any potential burn injuries when the grenade is ignited.
Previous chemical solutions used were considered irritant and potentially toxic. As such, newer solutions developed in 1990 were introduced that were considered less harmful. In the Model 90 variant, sugar is used as the fuel instead of sulfur, and magnesium carbonate is used as a coolant instead of sodium bicarbonate.