My valves are designed to fit virtually any plastic soft drink bottle, ideally the 2 Litre size.
It’s a good idea to pour around 3/4 litre of water into the bottle (aka, fill it to the bottom of the sticker) before pressurising each bottom to 70 psi or so. Add food colour to the water for a visually pleasing explosion.
No idea how long each valve will last. I still use one of the first I made but a few others have been destroyed by pellet impact or explosion damage.
Free postage UK & Europe. £11.70 for a pack of 5.