The EX612 is a 400A Dual Input AC Clamp Meter + NCV with AC Clamp-on meter with built-in dual Thermocouple inputs and Non-contact Voltage Detector The EX613 is a 400A Dual Input AC/DC Clamp Meter + NCV with AC/DC Clamp-on meter with built-in dual Thermocouple inputs and Non-contact Voltage Detector The EX622 is a 400A Dual Input AC Clamp Meter + NCV + IR Thermometer with AC Clamp-on meter with built-in dual Thermocouple inputs, NCV Detector and InfraRed Thermometer The EX623 is a 400A Dual Input AC/DC Clamp Meter + NCV + IR Thermometer with AC/DC Clamp-on meter with built-in dual Thermocouple inputs, NCV Detector and InfraRed Thermometer Available at Tequipment.NET Video by Extech.