Loaded with a generous combination of high quality components, near indestructible all-metal case and unique noise filtration system, Isobars offer the highest levels of protection. Robust surge suppression circuits with sine-wave tracking offer extreme levels of protection against the heaviest surge conditions. Isobar's unique protection system combines large torroidal chokes, HF/VHF capacitors and multiple metal oxide varistors that remove high level surges and EMI/RFI interference. UltraBlok 428 offers 2 outlets arranged with standard wall socket spacing in a cordless direct plug-in format. Mounting tabs allow permanent connection via duplex switchplate screw. Surge suppression rated at 600 joules / 48, 000 amps offers high-grade protection. Diagnostic LEDs confirm power availability, line fault and protection status.