SurgePure's unique design of having only one MOV (metal oxide varistor) for any given surge path let's users know that our modules are either 100& operational or 0% operational, unlike conventional multi-element designs that are prone to degradation due to unequal stressing amongst the paralleled MOV's leaving users wondering how adequate their surge protection really is. SurgePure's encapsulated MOV's insure the thermal integrity of critical surface areas and maintains functional MOV integrity by special heat-sinking characteristics of encapsulant. SurgePure's Single MCOV Thresholds insure 'Nano-second fast' response times critical to protecting and isolating even the most sensitive down-line circuitry and components. SurgePure's fuse-link integrity is 'always' maintained, and does not 'open' until entire surge capacity is fully utilized, unlike conventional designs that vaporize or open the 'fuse' long before the claimed surge capacity is engaged and utilized. The design-safety of SurgePure's 'concealed fuse-link' and 'safety surge cushion' eliminates the most feared result of lead ionization and vaporization into 'plasma-arcing' within the SPD which creates a highly explosive 'bomb-like' catastrophic SPD failure. Since the real-world purpose of a SPD System is to eliminate these types of hazards of "Electrical Pollution", nuisance type SPD failures are unacceptable! With the SurgePure Power Quality and Protection System you'll only buy it once.