The 3 1/2" x 3 1/2" ViewCatcher is constructed of durable ABS plastic to hold up to the elements and provide years of use. It is coloured a #5 grey to help judge value and has a small sight opening in the center that enables artists to see "true" colour. It can be held at different distances and the adjustable opening can be oriented horizontally or vertically to help find just the right composition.