american floor mats fit-lock 3/8 inch heavy duty rubber flooring - interlocking rubber tiles (24" x 24" tile) solid black 4' x 6' set (6 tiles total) - exercise mats, home gym sets american floor mats fit-lock rubber tiles are interlocking rubber floor tiles that easily and seamlessly lock together to protect floors around weight rooms, fitness centers and home gyms. fit-lock interlocking rubber tiles are made of commercial grade, recycled rubber, giving the matting added strength and durability. furthermore, these tiles will lay flat, are non-porous.