Soda siphon

The soda siphon (sometimes spelled syphon), also known as the seltzer bottle, siphon seltzer bottle, or just siphon) is a device for storing and dispensing carbonated beverages (typically carbonated water) while maintaining the internal pressure, thereby preventing it from going flat. The carbonated beverage is dispensed using the internal pressure of the bottle, so the setup is not a true siphon in its operation.