A solid state pulser, designed and constructed by PLEX LLC, has been tested at the Naval Research Laboratory. It has achieved more than 11,500,000 continuous shots at 10 pps and generated 200 kV, 4.5 kA, 300 ns pulses, and the standard deviation time jitter of the output voltage was less than ± 1 ns. The pulser consists of a 12 stage Marx, coupled with a 3rd harmonic stage, a main magnetic switch, a compact pulse forming line used as a transit time isolator, and a resistive load. Each Marx stage uses an APP Model S33A compact high voltage switch that is comprised of 12 series connected thyristors. The Marx has an efficiency of 80% based on thermal measurements.