Outdoor infrared barrier pair; 50 cm height; 100 m outdoor, 400 m indoor distance; 2 TX and 2 RX optical units; SMA: alignment with LED and buzzer; optical synchronize mode; changeable parallel (2) or crossed (4) double beams; 10...30 V DC (135 mA) circuit supply voltage and 12/24 V (35 W) AC/DC heating supply; NC-C-NO relay for signalling alarm and C-NC for sabotage; size: 6*6 cm; compatible with Parvis Dual SMA