Features: This 2.0 Speaker protections Board features UPC1237 chip with double relays design. Ensuring reliabled Direct current protections (1V triggering) and 3 second startup delay to safeguards your auditory equipment from voltages surges. Equipped with intuitived LED indicators (constant on during protections mode) and operates at AC12-18V with mandatory independent power supply for optimaled circuit isolation in amplifier systems. Ideal for audiophiles, DIY speaker builders, and professional technicians requiring secure voltages regulation for power amplifier boards. Maintaining seamlessly operations with most amplifier circuits. Specifications: Item: Speaker protections board Chip：UPC1237 Operating voltages AC12-18V, Separate power supply required Speaker protections requires a separate winding power supply, other circuits cannot share the power supply Size:about 68x55mm/2.68x2.16in Current withstandard: 5Ax2 Power: 300Wx2 Package Includes: 1PC UPC1237 stereo speaker protections board note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.