Premium Power Plyo Boxes have a stable square frame and a large landing area. This heavyweight plyometric box is a solid choice for plyometrics training. Platform is covered with an extra-thick mat and the perimeter is rounded for added safety during exercises. Square tubular steel construction. Tops are reinforced 3/4" plywood covered with 1/8" solid rubber mat. Stackable for convenient storage. Use indoors or outdoors. Black. Set of 4 (12", 18", 24", & 30"). With receipt of product, instructions are provided to view and download various helpful Plyo Box training videos.