Abstract: A movable member of a grille or shutter is slidable with respect to a stationary member through tongue and groove or other slidable connections, between a fully open and a fully closed position. Both the movable member and the stationary member are provided with corresponding cross bars which are spaced both vertically and equally. Facing upright rails, such as at the center, of the movable member and fixed member are provided with opposed grooves, each for reception of a vertically placed bar magnet. The magnets are placed with their opposite poles facing each other, so that the magnets will attract, rather than repel. Preferably, the closed position of the movable member is the upper position, and the magnets are directly opposite each other in this position.