D-Tek Select refrigerant leak detector has outstanding sensitivity and reliability. Equally sensitive to CFCs, HCFCs and HFCs and all refrigerants including R22, R134a, R410a, R507 (AZ-50), it eliminates resetting or switching for different refrigerants. Variable intensity audible signal grows stronger as you approach the leak, fainter as you move away. Uses 800-hour life infra-red sensing cell. Yellow LEDs light progressively to show leak magnitude. Green LED ‘ON’ indicator begins to flash when charge is low. High/low sensitivity switch allows you to cut back sensitivity when close to the leak, making it easier to pinpoint its exact source. High efficiency pump maintains continual flow of air through the sensor for instantaneous reaction to ambient refrigerant. Flexible probe and rubberised grip for easy use and comfort. Unit includes sensor, NiMH power cells, 240 volt charger and 12 volt cigarette lighter plug with cords for recharging, 10 spare filters and hard plastic carrying case.