I bought a couple of the payloads for a laugh 'cos they were on eBay for next to nothing. they were about 80mm in diameter, and at least 30cm long. charge in the base, electric ignition, and the body of them is absolutely packed with confetti. you would not believe how much you can pack into that volume when it's optimally folded.
I wanted to try one, so I ductaped it to a plank of wood, put it facing out the back door, and hooked it to a 12V 30A power supply.