Used, malfunctioning 9V volt battery operated smoke AND fire detectors
For repair, parts or science experiments
Kidde PI9010 Dual Sensor Photo / Ion detectors - utilizes both PhotoElectric and Ionization detection
When a fresh correct model battery is inserted, all three units go in to continuous "chirp" mode, despite reset attempts. All have been warrantied out by Kidde, but I would rather give these to some one who could use them, than throw them away.