One of the most popular accessories for the 9 by 12 Guerrilla Box. Fits perfectly under the sliding palette and leaves room in the Guerrilla Box for storing up to ten 37-ml paint tubes or other supplies underneath. When the box is in use, clamp your Brush Tray to the side of your Guerrilla Box or to the end of the palette to expand your workspace while painting. Basswood laminate.