PVC Extrusion Channel Frame, Black. Single or double-sided display. Ideal for displaying double-sided display in windows. Will accept material up to 4.5mm thick. Format - A3 Portrait (Opening on top side). Graphic size: 420mm H x 297mm W. Frame Overall Dimensions: 320mm W x 443mm H x 21mm D. The individual components, extrusions and joning corners, necessary for making custom sizes are available for purchase . The 'H' Extrusion and 'I' Extrusion) are available in 2.4m lengths.