An object is to provide a glow plug in which a gap can be prevented from being generated between a ceramic heater and a cylindrical member even at the time of use in an internal combustion engine, etc. The invention consists of a thin sheet of suitable fabric with ends long enough to extend beyond the sides of the windshield into the space between the car door and the door jam. Also the present invention is related to methods of preparing the novel 21-hydroxy-6,19-oxidoprogesterone analogues.