Bosu Balance Trainer + 3 Bosu Powerstax Risers. Improve the versatility, intensity and usability of the BOSU® Balance Trainer, and add an adjustable resistance training tool to your workouts with BOSU® POWERSTAX™. Each BOSU® POWERSTAX™ is designed to elevate the BOSU® Balance Trainer by 4 inches, partially stabilize the BOSU® Balance Trainer in a platform side up or down position, and create unpredictable resistance challenges (or load) when filled with two to 35 lbs. of water. Similar to the BOSU® Balance Trainer, BOSU® POWERSTAX™ is ideal for all ages and skill levels, and is proudly made in the USA. Includes: 3 BOSU® POWERSTAX™ *BOSU® Balance Trainer