This is the Repair Kit ONLY for the MPG401 All Metal Seal, Inverted Magnetron Pirani Gauge. Repair Kit Includes: Pirani Element with glass feedthrough, screw fitting, copper seal, anode extension piece, anode complete, ignition aids, seal HNV100 and centering ring. For detailed instructions on how to replace MPG400/401 maintenance kit parts, see .pdf below, pages 17 thru 23. (This pricing is for the Repair Kit Only, pumps, controllers, sensors sold separately.)