The INNOVA 3340 Automotive Digital Multimeter is the pros choice for a high-quality multimeter. The pro quality features help pinpoint engine problems while the 10 MegOhm impedance prevents damage to the ECU. It Includes temperature probe to measure temperature in both Celsius and Fahrenheit. Also use the inductive pick up to vehicle RPM (including coil on plug vehicles). This unit provides hands-free testing with test lead holders. Additional features include auto-ranging, auto shut-off, over-load protection, automatic zero adjustment and reverse polarity protection. The min/max and hold buttons save retrieved data and the rugged corner guards provide drop protection. The INNOVA 3340 is great for testing alternator diodes, duty cycle, solenoids, breaker points, wiring, switches, and more.