These soft plyoboxes are designed to be less intimidating than steel boxes for the developing athlete. Standard 28"x28" blocks. The 3" block is built with 2.2# density polyethylene foam, other sizes with 1.8# which provides stability, shock attenuation, and performance. Boxes are secured for stacking with industrial strength hook and loop fasteners and have a durable vinyl cover. All boxes are less than 28 lbs. and have two reinforced handles for portability. Available in 5 sizes or a set of 5 (1 of each size).