The PB-IN-HF series is the flagship of the TAKEX range of infrared photoelectric beams. By synchronizing 16 beam paths between Transmitter and Receiver, the PB-IN-HF series offer unrivaled stability in perimeter security. Coupled with channel separation and environmental (anti-fog) circuitry, the PB-IN-HF series has earned worldwide recognition as the standard our rivals aspire to. For distances up to 50m (165ft) outdoor / 100m (330ft) indoor. 4 Synchronised High-Power Beams. Selectable 4-Channel Beam Frequencies. Double Modulated Beam for unsurpassed Light Immunity. Monitor Jack for alignment with Multi-Meter. Audible Alignment Tone. Environmental (anti-fog) Monitoring Circuit. Dynamic A.G.C. Circuit. Frost Resistant Cover.