The TR-2019B current probe is originally designed to plug directly into a Dranetz-BMI Model 658 and require an adapter cable. The CA4300 adapter cable converts the model 658 probe connector to a hypertronics type connector that allows the TR-2019B current probe to plug directly into the PX5 family of products as well as the Series 61000 current module 61MAC. Current probe frequency range: 30 Hz to 5KHz Range: 50A-300A RMS 30Hz-5kHz Max conductor size 52mm Requires cable adaptor CA4300 1 to 300A RMS current transformer Used with the 656, 658, and PP4300