American Barbell Wood Plyo Box - 30x24x20This jump box is built for safe, effective plyometric training at any skill level. Its puzzle piece design allows for flat shipping and easy assembly. Heavy duty plywood and inner bracing system keep this box solid through heavy use. 30 x 24 x 20 Birch Plywood Inside support structure SAFETY WARNING: Do not use this jump box without a spotter. Use only on Rubber flooring surfaces; any other surfaces can be a slip hazard.