Collapsible Stackable Sturdy Aluminum Construction will not Shatter or crack Metal hinges designed for heavy use Rounded corners- No sharp edges! This slant board has an ideal writing angle (approx 20º) and folds to less than half an inch. Made of rugged aluminum, it is both extremely durable and lightweight. Non-slip edge strip holds board in place when used. Low profile metal clip is easy to manipulate. Writing surface measures 12" x 12".