Personal Radiation Detectors (PRDs) are pager size high sensitive devices for the search for the nuclear and radioactive materials. The high sensitivity and fast response time to the variations in the ambient radiation levels clearly distinguish PRDs from family of the electronic dosimeters which are mainly used for the precise dose and dose rate measurements. The PRDs are carried in pockets or clipped to a belt. They automatically monitor environment and alert user in case of the radiation danger. The main features of Polimaster’s Personal Radiation Detectors are: * Gamma and gamma/neutron radiation detections; * High sensitive, small and lightweight; * Non-volatile memory to store history events data; * Low power consumption; * Easy-to-use, two-button interface; * Reduced user training; * PC communication interface; * Capability to record gamma spectrum and transfer data to PC or PDA for radionuclide identification analysis