Each Adapter holds two wet panels. Use with Guerrilla Boxes, Guerrilla Adjustable Wet Painting Carriers, Guerrilla Wet Painting Totes and Guerrilla Hand Porters. Each Adapter fits inside the next size up (nesting) - this Adapter Set fits in a 12 by 16. This set includes two adapters: 1 each 9 by 12 and 11 by 14 to fit in a 12 by 16 Guerrilla Box, Carrier or Adapter. Basswood laminate with stainless steel clips.