A non-pyrotechnic item that makes a loud bang!  Easy to use, just make sure your sure about where and when to set off.

Instructions are found on the back of the bag.  The pouch contains a small water bag inside.  Using your thumbs, find it and press to pop it.  You will feel and hear it pop. 

Give the bag a little shake to mix with the powder inside and toss it away from you.  

The bag will inflate until it bursts.  At which point all you have to do is wait for the inevitable bang to follow.

If the bag doesn't pop after inflating, bravely pick up the bag, give it a little shake and toss it away again.