A cake firework, also known as a multiple tube device, is a firework comprising a series of Roman candles, small aerial shells, or a combination of both, connected together by a high-speed fuse.[1] Typically, the internal fusing is set to fire each tube in series, or to fire several tubes at the same time, or a combination of these. Typically a cake will resemble from the outside a simple cube or other rectangular covered shape; after firing, a large number of cardboard tubes (the candles) will be visible in the top of the firework (the paper cover having been blown off by the discharging stars). In a traditional cake, all the candles point upwards; a variant is called the fan or angle cake.
Cakes are one of the most popular types of firework, as they can create spectacular and long-lasting effects from a single ignition while minimising safety concern. In the UK, the reclassification of aerial shells to Category 4 has popularised cakes as a method for achieving similar effects while staying within safety guidelines, particularly by firing multiple candles at the same time.
Cakes vary greatly in size, weight and duration. Some last only a few seconds and contain only a few tubes, while others may last for several minutes, contain upwards of 1,000 tubes, and measure over 1cuyd in size. Large "finale Cakes" containing dozens of shells up to 4inch-diameter are not uncommon, and some cakes, particularly those containing large amounts of dragon's eggs, can weigh over 100lb prior to discharge.