Le Maitre Long-Duration Gerbs
Plumes of silver or gold sparks of varying height and duration, shoot up to create a glittering effect.
The first number shows the burn time (in seconds) and the second number shows the height (in feet). The height is defined as the top of the main plume, some sparks will go higher. For example: a 1/4 x 20 is a gerb of 1/4 of a second duration that reaches a height of 20ft.