Help your orchids thrive with a Windowsill Humidity Tray. Plants sit on the tray's upper grid platform and excess water pours into the tray below. As the water evaporates, it generates humidity for your orchids. Made from polystyrene, the Windowsill Humidity Tray measures 26" long x 6" wide x 2.25" deep. The base of the tray measures 3.5"wide.