Disclosed may be an intermediate surface for supporting a small paver, wherein the surface can also be used to exchange heat with the pavers. The interlayer insulating film 11b in the reflecting portion R has a corrugated surface formed by concave portions and convex portions. The plate is coupled to the threaded body. The cradle is rotated and released from the structure responsive to a sensor for contact within a drop impact zone on the contact surface of the moving sled.