Right and left hinged palette extensions double your working space for the 9 by 12 Guerrilla Box. Includes parking slots for the Hang-Up Brush Caddy and holes for brushes. Aluminum "standoffs" keep it from touching the Guerrilla Box sliding palette when closed (Note: remove the "standoffs" when used in conjunction with the Backpacker Watercolor Palette or Covered Palette Tray). Easily attaches using existing pilot holes. (NOTE: With the Palette Extension Kit installed, you will be able to carry one fewer wet panels in the Guerrilla Box lid.) Mounting screws included. Basswood laminate with aluminum hinges.