The Box of Fireworks is an item released on June 28 2013 to celebrate Independence Day on July 4. It was originally released in 2013 and is a premium item that can be purchased in the game using premium currency, donuts.
This item is a limited time item which means the item will be removed from the store after the event and will no longer be accessible in the game. You will need to wait until the next time this item is re-enabled for purchase to be able to buy this item for your Tapped Out city.
The Box of Fireworks is better known as a decoration and can be obtained both in the decorations section of the store or under “premium stuff”. You need to purchase this decoration using donuts which means you cannot simply use the money you’ve earned in game.
It is accessible at level 5 and will give 2.25% bonus money and XP to all jobs for your Tapped Out city.
If you do not see this item in the game then that means the item has expired and you will need to wait until the next event with this decoration to be able to purchase one for your game.