The Humidity-Drip trays allow you to use pots with drain holes without worrying about excess water pouring out and causing damage to furniture and they are good for your plant. Overflow water passes through your pot and collects in the tray where the settled water evaporates and helps offset the loss of transpiration, which is the loss of moisture through the leaves. This tray is made of heavy duty plastic and has raised feet. Just wash the tray with mild soap and water occasionally. Simple design and black color don't compete with the style and color of your pretty plant pot. Outside dimensions are approximately 12.25 inches by 8.5 inches by 1.25 inches deep and inside dimentions are approximately 11.5 inches by 7.75 inches by 0.75 inches deep.