Get a posture-perfect writing surface. A 20 degree angle compensates for fatigue in the back neck shoulder and eye muscles. Enhances concentration too. Economy Extra Large Slant Board is made of sturdy corrugated plastic. It folds flat for storage. It s made the same but the surface is larger 12 x 18 30.5cm x 46cm . Sold as Single Unit Helps reduce back neck and shoulder pressure and eye strain Angled for optimal positioning Extra-large surface area with low-profile metal paper grip-clip Lightweight unit folds flat for travel and compact storage