The ETA-S15L features noise filtering for eliminating unwanted Radio Frequency Interference (RFI) that is commonly introduced into AC lines by nearby radio transmitters or wireless products. EMI filters are also incorporated to reduce noise from Electromagnetic Interference (EMI) generated by items such as electric motors and switching power supplies.

Unstable AC Mains voltage is one of the main reasons for equipment failure. The amount of energy that can be injected into the power system can be immense with voltages reaching 6kV or amperage peaks of 3000A. These spikes are very fast and usually only last for a very short period of time. The AP-S15L's circuitry is very fast and can suppress unwanted energy within a nanosecond response and sustain the suppression up to 2 milliseconds, thus ensuring virtually trouble free protection. The AP-S15L has incorporated a front panel pull-out dimmable LED tube light to light a rack,. The rear of the rack can be illuminated using the optional 16" gooseneck LED lamp connected via an XLR style socket.