Depth and quantity together: 24 tiles arrive across two boxes, each square 24 by 24 inches and a full 0.79 inch thick. That extra depth is what keeps a dropped dumbbell from reaching the concrete and what stops the thud of jump work traveling into the rooms next door. Rubber on the working face gives grip and takes abrasion from shoes and equipment feet, while high-density foam beneath does the cushioning, the two layers fused through an adhesive-infused bond. Forty-eight detachable borders finish the exposed edges and the outer tiles can be trimmed with scissors around door frames. Laid over tile, marble, hardwood or carpet, the surface protects the floor beneath through heavy training.