The FLIR DM64-NIST True RMS HVAC Digital Multimeter with NIST Calibration and Temperature Measurement is the only multimeter HVAC technicians need, providing an unmatched feature set and high-quality measurements at an affordable price. This digital multimeter is easy to use and has been built to last, offering long term stability and robust build quality for field use. The DM64-NIST is the right choice for professionals installing, inspecting and maintaining HVAC systems.