Grate

Grates are foreground blocks which allow liquids to fall through while remaining solid for everything else, acting like a drainage system.

Grates can be toggled open and closed when triggered via wire. An open grate is transparent, allowing light and liquid through, while a closed grate is opaque and acts as a solid block. If a grate is triggered while liquid is passing through it, the grate holds the liquid until it is opened again or a player uses a bucket or sponge to remove it.

Bubbles function as the opposite of grates, acting as background objects which prevent the flow of liquids through them.

Trivia

 * The tooltip for the item, which is "They'rrrre Great!", is a reference to mascot Tony the Tiger, who says this line in ads for Frosted Flakes.
 * It could also be a play on words