Covering a full 96 square feet takes 24 tiles, which is why this one arrives as two boxes rather than one. Every 24-inch square is built as a 0.55-inch rubber and foam laminate with the blue-flecked rubber facing up, giving grip for lifting and a surface that dropped plates will not gouge. The foam underside handles the impact and keeps the rumble of a treadmill from carrying through the structure of the house. Forty-eight borders come in the box to finish the perimeter, and the outer tiles can be cut down with scissors so the floor meets the wall cleanly. At 61 pounds the completed run stays where it is laid over concrete, tile, wood or carpet.