The SineTamer© RM series of units blends outstanding high-energy “impulse” suppression with excellent “ring-wave” transient protection utilizing our Frequency Attenuation Network®. This durable device is intended for general purpose and sensitive/critical load applications. The RM-ST120 is typically installed at small service entrances up to 800 amps, distribution and sub-distribution panels. The circuit design of the RM series does not shunt transients to ground, but utilizes discrete mode circuitry to create a near equipotential bond amongst all conductors to dissipate surge energy. The units are all bidirectional enabling them to suppress any surges from ground between any connected phases. This economical device has features that are not available in devices costing many times its price. Its compact size makes installation a breeze. Maintenance Free operation and 15 Year Unlimited Free Replacement Warranty provide peace of mind. Standard unit is Type 2 10kA UL Nominal Discharge Current, Optional Type 220kA IN is available