It fits a standard 1

The Lennox 17J56 Flame Sensor is a critical OEM replacement part engineered for precise flame rectification in residential and light commercial Lennox furnace units

The Williams P271100 Flame Sensor is a critical OEM safety component engineered for precise flame rectification in Williams Forsaire counterflow furnaces

While it functions electrically the same as straight models

Key Benefits Universal Compatibility: Specifically engineered to adapt Trane Gemini gas valves into the footprint of older White Rodgers 36E and 36F series hardware

Honeywell 21500 Filter 30067439-890 It fits a standard 1Honeywell 21500 99. 97 HEPA Filter For 150CFM W O CPZ