The Martin pro-draft professional parallel straightedge is cutting edge technology. A short list of the Pro-Draft"s features include: Aluminum body for strength and stability, Anti-warp cast acrylic bottom with ink edges, locking device to lock in any angle that you would like to draw, and anti-static rollers to avoid smudges to your drawing. Size 48-inch. (Suggestion: Consider a straightedge about 6-inch shorter that your table to allow for other materials, etc).