15mm pyro cartridges are small pyrotechnic cartridges that are commonly used in various pyrotechnic devices and effects. These cartridges are typically made of aluminum or paper casing and contain a pyrotechnic compound that is activated by firing from a starting gun. The pyrotechnic compounds used in 15mm pyro cartridges can vary depending on what type of effect is required. For example, some cartridges contain a compound to create a light effect, while others contain a compound to create a loud sound effect.