The ESP Digital QC offers very powerful protection from the damage and downtime caused by electrical surges, spikes, over voltage, EMI/RFI noise and wiring faults. Today's Digital QC is the evolution of the original, ground-breaking ESP design which came to market in the 1980s. To this day, it remains one of the bestselling professional-grade surge protectors in the world - having sold millions of units. Unlike standard surge protectors and power strips that offer limited protection (often using only metal oxide varistors (MOV)), the Digital QC combines gas tubes, silicone avalanche diodes and metal oxide varistors into a patented circuit that does not degrade over time and provides very robust protection. The Digital QC is used by many of the world's leading technology companies to safeguard their electronic equipment, optimize performance and protect against data loss. ESP products feature a lifetime warranty on the product and a 5 year, $100,000 connected equipment warranty. Like all ESP products, the Digital QC is proudly made in the USA with the highest quality components.