The Fireworks block (coloquially Firework blox) is a special version of the Bomb block that appears on both Boom Blox and Bash Party, its apperance is a black block/ramp/cylinder with a firework on it pointing upwards (unless you turn it on its side) and like the bomb blox it is triggered when hit with any weapon (with exception to the Vanish/Vapor bomb) or chain reaction which leads to it propelling itself upwards and exploding with some special effects (in this case a firework explosion), this is useful for levels where you need a propelled explosion