The pastel box insert is an accessory for the sienna plein air pochade box. Two sizes of pastel box are available to match the two sizes of pochade box. The storage area and lid are lined with foam to keep your pastels protected during transport. The pastel box will accommodate a range of different pastel lengths and widths. A vertical divider helps with organization and keeping warm and cool colors separate. The pastel box is held in place with the large set of palette blocks included with the pochade box. The L pastel box has two storage compartments that each measure 5 ¼ in x 7 ¾ in.