The extra-wide, staggered ribbed surface of the composite plastic Classic Slant Board is the ideal platform to increase extension in the lower and upper back, to stretch the fascia on the bottom of your feet to relieve the pain of plantar fasciitis, and for calf stretches. You select the incline angle perfect for you, and gradually increase the incline as you progress. The large, ribbed surface provides a safe, non-slip, functional platform for all your lower body stretching and positioning exercises. The 4-position incline and calf stretcher board is made of a super strong composite plastic, tested to hold over 400 pounds. It adjusts to 4 levels and folds flat to store conveniently. Levels are 10, 15, 20 and 30 degrees. The last slot on the incline board makes an excellent hand-hold for further stretching. The Slant Board is also an ergonomic, comfortable and adjustable foot rest for use at your desk or workstation used to relieve the tension in your lower legs, ankles, and feet when sitting for long periods.