A choice of feature sets is offered through three models:

ION7300: revenue-class power and energy metering, harmonics measurement (to 15th), analog I/O, digital outputs, RS-485 port, and web server (Ethernet option only).
ION7330: adds event logging, min/max logging, 32-channel historical logging, setpoints, digital inputs, two RS-485 ports, modem, gateways, and email (Ethernet option only).
ION7350: adds 96-channels of historical logging, dip/swell monitoring, harmonics measurement to 31st, waveform capture, and call-out on alarm

Characteristics (some features are optional):

Panel-mount, LCD display, available without display
3-phase, 4-quadrant metering, class 0.5 revenue-accurate (IEC & ANSI)
Voltage, current, power, frequency, power factor, demand, energy, and time-of-use metering
64 samples/cycle waveform capture, dip/swell monitoring, harmonics measurement (up to 31st)
Sequence-of-events, coincident minimum/maximum, historical trends, and high-speed snapshot recording, 1 ms resolution timestamping
4 analog inputs, 4 analog outputs, 4 digital status/counter inputs, 4 digital control/pulse outputs
12 setpoints for alarms and control, 1 second response, multi-condition, call out on alarm
5 communication ports: Ethernet, modem, 2 x RS-485, RS-485, front panel optical, Profibus port (ION7300 only)
Protocols: Modbus RTU slave, Modbus TCP, DNP 3.0 (ION7330/7350 only), MV-90
Ethernet and modem gateways to 31 devices on RS-485 port
On-board web server, email for alarms and data logs