Our Twin photoelectric beams are designed to meet the highest standards of quality and reliability for photoelectric beam intrusion detection. Unique twin beams are synchronised to work together to reinforce range and stability in severe weather conditions. For distances up to 60m (200ft) outdoor / 120m (400ft) indoor. Choose from 4-Channels (selectable) for use in 'stacked' or 'in-line' systems without crosstalk. Synchronised Twin Beams for reliable detection. Double Modulated Beam type ensures unsurpassed immunity to direct and reflected sunlight and vehicle headlights. Multi-Meter Test Points to accurately monitor alignment voltage. Frost Resistant Cover minimises nuisance alarms in harsh weather. Automatic Gain Control for maximum stability.