The AQY212GHAZ is a 4-pin PhotoMOS relay designed for high-capacity switching with a continuous load current of 1.1 A and reinforced insulation providing 5,000 V AC I/O isolation voltage. This compact DIP package device features an on-resistance of 0.34 O (typical) and operates with an LED forward current of 5 to 10 mA, delivering turn-on and turn-off times of 1.3 ms and 0.1 ms respectively. The relay supports AC/DC dual-use operation at 50 V load voltage with a peak load current capability of 3.0 A, and operates reliably across a temperature range of -40°C to +85°C. It is commonly used in measuring instruments, security systems, and alarm devices where electrical isolation and high switching capacity are required, offering improved performance compared to mercury or mechanical relays.