Features and USP: The S331L, which covers the 2 MHz to 4 GHz range, brings a high level of performance to return loss, cable loss, and Distance to Fault (DTF) measurements. It has the highest RF immunity of any site master. A sweep speed per data point of 1.5 msec (typical) saves technicians time and enables easier identification of intermittent problems in real time. Helping ensure measurement accuracy is the standard built-in InstaCal, which provides fast one-connection calibration anytime, anywhere. The S331L also features a standard built-in power meter for easy, convenient testing of RF power in field environments.