AC Power Filter Power Conditioner - WAudio AC Power Purifier with Surge Protector PHASE DETECT - Phase and the ground wire connection of AC source can be detected automatically. OVERLOAD PROTECTION - The sockets will be powered off when total current over 15A, press RESET button to restore power supply. VOLTAGE PROTECTION - Its circuit detects dangerous voltage irregularities and provides the highest level of surge & spike protection. HEAVY DUTY DESIGN - Metal casin with thickness aluminum plates, come with 6pcs hospital grade filtered outlets and 4pcs industrial grade direct outlets. POWER CLEAN - It ensures that all devices connected to W-3900 receive clean & filtered power, which reduces noise and ensures better sound and picture quality from amplifier, DJ equipment, home recording, projector, TV, computer, and other electronics.