Front view of the Klein Tools MM325 digital multimeter against a white background. The orange and black device features a large digital LCD screen at the top showing a test pattern. Below the screen are grey buttons for data hold and a backlight, a large central rotary selector dial for various testing functions, and three input terminals at the bottom for test leads.
Angled three-quarter view of the MM325 multimeter standing upright on its integrated black kickstand. The device is shown from the left side, highlighting the rugged orange protective overmold and the clear markings on the central function selector dial.
Front-facing studio shot of the MM325 multimeter with the display off, showing the orange housing and black interface. The dial is set to the OFF position, and the CAT III 600V safety rating is visible at the bottom right.
Rear view of the MM325 multimeter showing the back of the orange and black housing. One red test lead is clipped into a dedicated storage slot on the right side, and a grey safety cap for a test lead probe lies on the white surface below.
A set of red and black test leads for the multimeter, coiled together against a white background. The set includes two pointed probes with red and black handles and two right-angle connectors, with one grey safety cap shown separately.
Product infographic featuring the MM325 multimeter with text and icons highlighting its technical capabilities. The graphic specifies manual ranging and lists measurements for 600V AC/DC voltage, 10A DC current, 2M Ohm resistance, 2-meter drop protection, and a CAT III 600V safety rating.
Annotated product graphic showing an angled view of the MM325 multimeter with yellow lines pointing to key features. Labeled features include Auto Power-Off, Backlight, Audible Continuity, Function Selector Switch, Lead Alert Protection, Battery Test, and Data Hold.
Rear view infographic of the MM325 highlighting back-of-tool features with yellow lines. Labels indicate a mount for an optional magnetic hanger, integrated test lead storage and holder, and the fold-out kickstand.
Close-up graphic focusing on the bottom input terminals of the MM325 multimeter titled LEAD ALERT PROTECTION. Two green LEDs are shown illuminating around the 10A and COM terminals to indicate proper lead placement for safe operation.
Action shot of a person using the MM325 multimeter to test a wall outlet. The multimeter is propped up on its kickstand on a grey countertop, showing a reading of 121.5V on its backlit blue display as the user inserts the red and black probes into an electrical socket.
A person's hands are shown using the red and black probes of the Klein Tools MM325 digital multimeter to test a small 9V battery on a wooden surface. The multimeter's backlit blue screen displays a reading of 9.04.
A worker uses the red and black probes of the MM325 multimeter to test a circuit inside an open grey electrical box mounted on a brick wall. The multimeter is propped up on its kickstand on top of the box, showing a reading of 239.5 on its backlit blue display.
A close-up view of a worker's hands holding the back of the orange Klein Tools MM325 multimeter, demonstrating the installation or use of an optional black magnetic hanger accessory. The background shows blurred electrical wiring and components within a panel.
Klein Tools Digital Multimeters (MM325, MM420, MM450, MM720) promotional video
Front view of the Klein Tools MM325 digital multimeter against a white background. The orange and black device features a large digital LCD screen at the top showing a test pattern. Below the screen are grey buttons for data hold and a backlight, a large central rotary selector dial for various testing functions, and three input terminals at the bottom for test leads.
Angled three-quarter view of the MM325 multimeter standing upright on its integrated black kickstand. The device is shown from the left side, highlighting the rugged orange protective overmold and the clear markings on the central function selector dial.
Front-facing studio shot of the MM325 multimeter with the display off, showing the orange housing and black interface. The dial is set to the OFF position, and the CAT III 600V safety rating is visible at the bottom right.
Rear view of the MM325 multimeter showing the back of the orange and black housing. One red test lead is clipped into a dedicated storage slot on the right side, and a grey safety cap for a test lead probe lies on the white surface below.
A set of red and black test leads for the multimeter, coiled together against a white background. The set includes two pointed probes with red and black handles and two right-angle connectors, with one grey safety cap shown separately.
Product infographic featuring the MM325 multimeter with text and icons highlighting its technical capabilities. The graphic specifies manual ranging and lists measurements for 600V AC/DC voltage, 10A DC current, 2M Ohm resistance, 2-meter drop protection, and a CAT III 600V safety rating.
Annotated product graphic showing an angled view of the MM325 multimeter with yellow lines pointing to key features. Labeled features include Auto Power-Off, Backlight, Audible Continuity, Function Selector Switch, Lead Alert Protection, Battery Test, and Data Hold.
Rear view infographic of the MM325 highlighting back-of-tool features with yellow lines. Labels indicate a mount for an optional magnetic hanger, integrated test lead storage and holder, and the fold-out kickstand.
Close-up graphic focusing on the bottom input terminals of the MM325 multimeter titled LEAD ALERT PROTECTION. Two green LEDs are shown illuminating around the 10A and COM terminals to indicate proper lead placement for safe operation.
Action shot of a person using the MM325 multimeter to test a wall outlet. The multimeter is propped up on its kickstand on a grey countertop, showing a reading of 121.5V on its backlit blue display as the user inserts the red and black probes into an electrical socket.
A person's hands are shown using the red and black probes of the Klein Tools MM325 digital multimeter to test a small 9V battery on a wooden surface. The multimeter's backlit blue screen displays a reading of 9.04.
A worker uses the red and black probes of the MM325 multimeter to test a circuit inside an open grey electrical box mounted on a brick wall. The multimeter is propped up on its kickstand on top of the box, showing a reading of 239.5 on its backlit blue display.
A close-up view of a worker's hands holding the back of the orange Klein Tools MM325 multimeter, demonstrating the installation or use of an optional black magnetic hanger accessory. The background shows blurred electrical wiring and components within a panel.
Klein Tools Digital Multimeters (MM325, MM420, MM450, MM720) promotional video
KLEIN TOOLS

Klein Tools Digital Multimeter MM325 600V Manual Tester (CAT III 600V Backlit LCD Lead Alert Voltage Current Resistance Diagnostic Appliance Meter)

In stock
SKU: MM325
$34.97 USD

Description

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Contractor-Grade Manual Ranging Digital Multimeter for Troubleshooting Residential Breaker Boxes and Appliance Circuits

The Klein Tools MM325 Digital Multimeter is a professional-grade electrical diagnostic instrument engineered to safely analyze circuits in residential, commercial, and light-industrial utility installations. Powered by manual-ranging technology, this high-performance electrical tester provides strict control and tracking accuracy across electrical streams measuring up to 600V AC/DC voltage and 10A DC current. The rugged housing is precision-built to withstand an absolute 6.6-foot drop on structural concrete surfaces while integrating an innovative LED Lead Alert protection matrix that guides proper test probe input seating. Certified with a rigorous CAT III 600V safety classification and configured with a 2000-count backlit LCD panel, this trade-focused service tool resolves low-visibility layout diagnostic challenges inside dark crawlspaces and main breaker boxes.

Best Used For:

  • Household Receptacle Troubleshooting: Diagnosing broken wall outlets, switches, and interior branch circuits by verifying line voltage levels.
  • Automotive DC Battery Testing: Identifying weak cells and tracing parasitic drains in low-voltage vehicle networks up to 10A configurations.
  • Appliance Component Checks: Verifying open heating elements and terminal integrity using explicit resistance parameters up to 2 MOhms.

Key Performance & Safety Features

  • Visual Lead Alert Matrix: Front panel warning LEDs illuminate dynamically to establish correct probe connection placement for the selected task.
  • 600V Dual Alternating/Direct Voltage: Comprehensive electrical circuit analysis capability supports structural wiring grid checks.
  • 6.6-Foot Impact Drop Survival: Tough elastomer body overmolding absorbs continuous mechanical shock from jobsite drops.
  • 2000-Count Backlit LCD Screen: High-contrast display window allows instant verification of metrics in low-light branch panel closets.
  • Integrated Battery Testing Node: Provides dedicated diagnostic testing configurations to evaluate cell energy states accurately under slight load.

What's Included

  • (1) MM325 Manual-Ranging Digital Multimeter
  • (1) Set of Premium Test Leads with CAT III/CAT IV Removable Safety Caps
  • (2) Heavy-Duty AAA Alkaline Batteries
  • (1) Step-by-Step User Manual

Technical Specifications

Specification Value
Brand Klein Tools
Model Number MM325
Display Type 2000 Count Backlit LCD
Voltage Rating 600V AC/DC
Current Rating 10A DC
Resistance Range Maximum 2 MOhms
Safety Rating Category CAT III 600V
Drop Protection Spec 6.6 Feet
Overall Tool Length 6.41 Inches
Overall Tool Width 3.13 Inches
Overall Tool Height 1.83 Inches
Net Tool Weight 8.8 oz.

Pro-Tip: When diagnosing continuity issues inside main electrical boxes, double-check your lead alignment via the Lead Alert system. Always execute a fast control measurement on a known live source circuit prior to testing dark wires, verifying your internal tester fuses are functional and your reading track remains accurate.