Thruline® RF Power Analyst 0.45 MHz to 2.5 GHz (elements sold separately). 1 W to 10 kW. Uses the same plug-in elements as the Model 43. PEP, Dual element, LED, Portable Wattmeter. Bright LED Display, Long-stroke keyboard and range switches. Built-In Power Supply and Charger The Model 4391A is a Rugged RF Power Analyst that monitors Peak Pulse Power, Peak Envelope Power, or CW Power during normal equipment operations in the forward or reflected direction. Designed for air navigational aids DME, ATC and other pulsed RF systems such as telemetry, radar, commandand control, etc. Package includes Wattmeter, RF Load, rugged HD carry case, 117 AC Power cord and manuals (as pictured). 4391M is military ruggedized version of the 4391A.