Abstract: A cylindrical tube with a screw threaded packing gland in the upper end carries an upper guide rubber with a plurality of packing rubbers stacked thereabove and engaged by the gland which applies the necessary pressure to seal the polish rod reciprocating within the stuffing box. A blow-out preventor assembly is situated below the upper guide rubber and comprises a cylindrical rubber portion surrounding the polish rod and having O rings sealed adjacent the upper and lower ends of the cylindrical rubber. An annular chamber is formed on the outer surface of the cylindrical rubber between the O rings and communicates with a source of fluid under pressure which can firstly apply pressure to the rubber surrounding the polish rod and shut off the well so that the stuffing box can be serviced and secondly, can act as an automatic blow-out preventor if the polish rod breaks.