This is a Pyrotronics F3/5A Smoke Detector that uses 80 micro Curies of Americium 241 as an ionization source. This device has 3 radioactive sources in it. These radioactive sources are americium 241 foil, which are located on the cap center post and 2 strips inside the ionization chamber. The device has been checked to confirm the sources are installed in the device. The device hasen't been checked to see if it works as intended and is sold as is. 
 
 The radioactive sources give off lots of alpha radiation and some low energy gammas. If you are using a pancake GM style probe it will send most off scale with the alpha radiation.