This versatile and value-packed tool offers an unstable rubberized top block for maximum core and ankle strength training. The Fitness Balance Trainer comes in a set of two, and is constructed of high-quality polyethylene covered with durable 18-oz. vinyl. Its measurements of 4" wide x 8" long top surface and 9" wide x 20" long base create a stable and sturdy foundation for powerful workouts such as Pistol Squats, L-Raises, and Inverted Handstand Push-ups.