.3000V adjustable, positive or negative polarity. This is aUNIVERSAL SYSTEM, which will work with almost any alpha / beta / gamma detector, although only gamma detector is included. PulseCounter software for multi-channel analysis (MCA), signal processing, spectrum reconstruction, etc.
This is a companion discussion topic for the original entry at https://www.ebay.com/itm/3-NaI-Tl-Gamma-Spectrometer-Spectroscopy-System-MCA-Ortec-456-3kV-Power-Supply-/143621996489