A test tube filled with magic snow powder that, when mixed with a little water, immediately expands to 100 times its original volume. The reaction creates a mass of fluffy white flakes, which can be kept for months by regularly spraying with more water, or can be left to dry out and reused over and over again.
Add water and the powder turns into fake snow
Expands to 100 its original volume
Spray with water to keep for several months
Leave to dry and reuse