Digital multimeters use red (positive) and black (negative) insulated test leads to capture voltage, amps, current, resistance, and continuity measurements. Also called DMMs, DVOMs, and digital multitesters, these portable and handheld diagnostic tools have digital displays with advanced features that provide fast and accurate readings. Typical uses include testing and troubleshooting wall outlets, light bulbs, batteries, extension cords, and appliances by electricians and contractors. Commercial and industrial applications include motor drives, computers, HVAC, power automation, and electronic equipment.