This is a shooting item. Basically, you hold it in your arms.
Gotta heft this thing! Hurrrgh!
After you grab this item, it'll rapidly release blast after blast of firecrackers that explode gaudily.
You can walk around and jump while holding the launcher.
You can also aim the launcher at different angles by tilting the Control Stick up or down.
Fire up or down!
Be safe and sensible when playing with fireworks.