Americium-241 source foil (gold-coloured item) soldered to a pedestal with user selectable exposure via screw-mounted shroud. Pedestal is part of a Pyrotronics® model F3/5A ionization technology smoke detector manufactured in 1971. Original activity of all source foils in the unit was 80 µCi of Am-241. The pedestal mounted source foil contained approximately 60 µCi Am-241 of the 80 µCi total. Shroud has been fully raised to show how source foil is mounted.