The Klein Tools MM325 is a manual-ranging digital multimeter rated CAT III 600V for basic electrical testing. It measures AC/DC voltage up to 600V with ±2% accuracy, DC current up to 10A, and resistance up to 2 MΩ. It also tests batteries, diodes, and continuity. Lead Alert LEDs indicate correct lead placement for safer operation. The backlit 2000-count LCD, kickstand, and 6.6-foot drop rating support daily field use. Auto power-off and data hold are included. Backed by Klein Tools' 1-year limited warranty.
What is manual ranging and when is it preferred?
With manual ranging you set the measurement range yourself via the dial. This gives control over resolution — useful when making many readings in the same known range, or in electrically noisy environments where auto-ranging can hunt between ranges.
Does the MM325 support True RMS?
No — it uses average-sensing, which is accurate on pure 60Hz sine-wave circuits (household 120/240V). For motors, variable-speed drives, or electronic ballasts, average-sensing can underread by 10% or more. Choose the MM420 for those applications.
What measurements does the MM325 support?
AC/DC voltage up to 600V, AC/DC current up to 10A, resistance, continuity with audible beep, and diode test. It does not measure temperature or capacitance.
What's the CAT rating?
CAT III 600V — covers distribution panels, branch circuit wiring, and most residential and commercial electrical work. Not rated for utility service entrance (CAT IV) work.
When would I choose the MM325 over the MM420?
When you consistently work in a known, fixed voltage range and prefer manual control, or when you work exclusively on residential 120/240V circuits and don't need auto-ranging or True RMS accuracy.
# Klein Tools® MM325 Digital Multimeter, Manual-Ranging, 600V **Model:** `MM325` **Brand:** Klein Tools **Category:** Multimeter > The Klein Tools MM325 is a manual-ranging digital multimeter rated CAT III 600V for basic electrical testing. It measures AC/DC voltage up to 600V with ±2% accuracy, DC current up to 10A, and resistance up to 2 MΩ. It also tests batteries, diodes, and continuity. Lead Alert LEDs indicate correct lead placement for safer operation. The backlit 2000-count LCD, kickstand, and 6.6-foot drop rating support daily field use. Auto power-off and data hold are included. Backed by Klein Tools' 1-year limited warranty. ## Specifications | Attribute | Value | |---|---| | Product Type | Digital Multimeter | | True Rms | No | | Auto Ranging | No | | Voltage Range Ac | 600V AC | | Voltage Range Dc | 600V DC | | Current Range Dc | 10A DC | | Resistance Range | 2 MΩ | | Low Impedance Loz | No | | Nist Calibrated | No | | Display Type | LCD | | Display Count | 2,000 | | Cat Rating | CAT III 600V | | Battery Type | 2 x AAA | | Overall Length In | 6.41 | | Assembled Weight Oz | 8.8 | | Barcode (UPC) | 092644693731 | | Warranty | 1-year limited | ## What's Included - Multimeter - Test leads with CAT III/CAT IV safety caps - Instructions - 2 x AAA batteries Source: https://www.jaspecs.com/klein-tools/multimeter/mm325-klein-tools-digital-multimeter-manual-ranging-600v/