CFF 3 - N - 1 Wood Puzzle Plyo Box - 20/24/30 inch - Great for Cross Training, MMA, or Plyometric Agility Training These 3 side plyo boxes save you money and space by combining 3 of the most popular size ploys into one. Ships flat to save on shipping costs, some Assembly Required Made of Cabinet grade 3/4 inch All edges are rounded over for safety ships flat to save on shipping 3 internal center supports for added strength Glue not included and we strongly recommend pre-drilling pilot holes. The main holes are pre-drilled.)