Demon rocket is new for 2017 and has 140g of powder inside. It is a 1.3g rocket so it has much more flash powder inside than the supermarket fireworks have.
You will get a burst from these big rockets will give an effective spread of over 80ft or over 25 metres.
Firework Setup Tutorials
If you are unsure how to setup our fireworks please visit the page linked below and watch our tutorials