Glass Lily Outflow 16MM L

It sounds like you're referring to a glass lily pipe outflow for an aquarium, typically used for filtration purposes. A 16mm size usually fits the outflow of a canister filter with a 16mm (5/8 inch) hose.

These glass lily pipes are popular in aquascaping and planted tank setups for their aesthetic appeal and the gentle flow they create, which is beneficial for plant growth and fish health. The glass construction ensures a smooth, clean look that blends well with the tank environment.