The CAT rating is a safety specification, not a quality grade · review
An automotive meter built around the one specification car electronics actually need — a 10 MΩ input impedance.
What the figures leave us with A focused automotive meter at eleven dollars, built around the one figure car diagnosis actually needs: a 10 MΩ input impedance, stated, so the meter does not load a sensor line and invent a fault. Nineteen ranges, automatic polarity sensing and alligator clips all belong on a car rather than a bench. It publishes no measurement category, no voltage ceiling and no ampere figure, and the 9 V battery is not in the box.
NO measurement category. NO voltage ceiling. NO ampere figure. NO count.
And nothing else on this shelf publishes an input impedance.
A modern sensor line carries almost no current. A meter that draws some changes the voltage it is reading.
Put a low-impedance meter across a throttle position sensor and the line sags. You read a fault that is yours, and a healthy sensor goes in the bin.
Ten megohms draws a fraction of a microamp at five volts. The circuit does not notice.
Actron states the figure and states why.
Which is worth separating, because the hub asks for the other one.
RANGES are the positions the dial selects. COUNTS are what the display resolves within a range.
A 2,000-count meter reads to 1,999. A 6,000-count meter reads to 5,999 — three times the resolution at the same range.
Nineteen ranges tells you how much the dial covers. It does not tell you how finely you can read it, and none of these four publishes a count.
Automatic polarity sensing: reverse the leads and the sign changes rather than the reading failing.
Automatic zero on volts, amps and battery tests.
Alligator clips in the box, which free both hands while the engine runs.
A foldout stand. A backlit display. A hold button.
None of that is a specification. All of it is what the tool is for.
Because of one word in its second bullet.
“Use to test diodes, batteries, FUSES, switches, solenoids, and relays.”
It tests fuses. It is not one.
Its own fuse, meanwhile, is not described anywhere on the page — only “overload protection”.
No measurement category, which the hub above says to read first.
No voltage ceiling at all, on a meter that measures AC voltage. Every other meter on this shelf that publishes a voltage states 600 V.
No ampere figure for the DC current it reads.
And no battery: nine volts, not included, alone among these four.
On sale at around 11 € on the American Amazon store at the time of checking.
Prices and availability are what Keepa reported on the date this page was updated; both move.
Prices quoted in this text were read on 8 October 2026. The live price is at the top of the page.
| Measurement category | NOT PUBLISHED. No CAT II, III or IV appears anywhere on this listing, which this shelf's introduction calls the specification to read first. In fairness to the tool, it is sold for automotive work at 12 V, where mains transient categories do not describe the hazard — but it also measures AC voltage, and the page gives no voltage ceiling at all |
|---|---|
| Voltage measurement | AC and DC, stated, with no maximum published. That is the gap on this page: every other meter on this shelf that publishes a voltage states 600 V. Battery tests are called out at 1.5 V, 9 V and 12 V, which is where this meter is meant to live |
| Current measurement | DC current, stated, with no ampere figure. Three of the four American meters on this shelf read DC current only; the Klein MM450 is the exception |
| Functions | 19 RANGES, stated — the only range count published anywhere on this shelf. AC and DC voltage, DC current, resistance; tests for diodes, batteries, FUSES, switches, solenoids and relays. The word "fuses" in that list is the reason this line was relevéd on the multimeter-fuses shelf: it TESTS them. A hold button retains the reading, and there is a low-battery indicator and overload protection |
| True-RMS | NOT PUBLISHED, and the ranging is manual across those 19 ranges. What it does have instead is AUTOMATIC POLARITY SENSING — reverse the leads and the sign changes rather than the reading failing — and automatic zero adjustment for volts, amps and battery tests. On a car, where you are often reaching into a loom with one hand, polarity sensing is the feature you notice |
| Display count | NOT PUBLISHED, as on the MM325, the MM450 and the KAIWEETS KM100 written beside it. It publishes a RANGE count instead — 19 — which is a different thing: ranges are what the dial selects, counts are what the display can resolve |
| Fuse | NOT PUBLISHED. Overload protection is stated; nothing says whether the current input is fused or with what. The page lists fuse TESTING among its functions and its own fuse nowhere |
| Construction and safety | 10 MΩ INPUT IMPEDANCE, stated "for proper testing of sensitive automotive computer circuits". That is the specification this whole tool is built around and no other meter on this shelf publishes it: a low-impedance meter draws enough current from a sensor line to change the voltage it is reading, which is how a healthy sensor gets replaced. A backlit LCD, a foldout stand, and a downloadable manual with test procedures in English, Spanish and French |
| Supplied | Color-coded leads, alligator clips, a foldout stand and a quick-start guide. The 9 V battery is explicitly NOT INCLUDED — the only meter on this shelf sold without its cell, at $10.99, the cheapest here. The alligator clips matter on a car: they free both hands while the engine runs |
| Amazon reference | B0006V2BP0 |
| EAN | 0021467076650 |
At $11, it is the 1 cheapest of the 7 models in this category published here.
Because a modern sensor line carries almost no current, and a meter that draws some changes the voltage it is trying to read. Put a low-impedance meter across a throttle position sensor and you load the line, the voltage sags, and you diagnose a fault that is yours. Ten megohms draws a fraction of a microamp at five volts, which the circuit does not notice. Actron states the figure and states why — "for proper testing of sensitive automotive computer circuits" — and no other meter on this shelf publishes an input impedance at all.
They are not the same measurement and this page gives the first. Ranges are the positions the dial selects — so many volts DC, so many ohms, and so on. Counts are what the display can resolve within a range: a 2,000-count meter reads to 1,999, a 6,000-count meter to 5,999, which is three times the resolution at the same range. This shelf's introduction asks for counts, and neither it nor the MM325, the MM450 or the KAIWEETS KM100 publishes one. Nineteen ranges tells you how much the dial covers, not how finely you can read it.
It is a question to settle against the work, not against the price. This is sold as an automotive tool: 12 V systems, battery tests at 1.5, 9 and 12 V, sensor circuits. At those voltages the mains transient categories this shelf's introduction describes do not describe the hazard. The problem is that the page also offers AC voltage measurement and never states a ceiling, so nothing tells you where the tool stops. Follow the manufacturer's instructions for the work you are doing, and for anything on a mains installation use a meter whose category is printed.
Same category, nearby prices, between measuring instruments. What remains is the specifications every one publishes — half empty, a column is no use.
| Model | Price | Voltage measurement | Current measurement | Functions |
|---|---|---|---|---|
| Actron Automotive multimeter, 19 ranges | $11 | AC and DC, stated, with no maximum published. That is the gap on this page: every other meter on this shelf that publishes a voltage states 600 V. Battery tests are called out at 1.5 V, 9 V and 12 V, which is where this meter is meant to live | DC current, stated, with no ampere figure. Three of the four American meters on this shelf read DC current only; the Klein MM450 is the exception | 19 RANGES, stated — the only range count published anywhere on this shelf. AC and DC voltage, DC current, resistance; tests for diodes, batteries, FUSES, switches, solenoids and relays. The word "fuses" in that list is the reason this line was relevéd on the multimeter-fuses shelf: it TESTS them. A hold button retains the reading, and there is a low-battery indicator and overload protection |
| KAIWEETS CAT III 600 V multimeter, double fused | $12 | AC and DC, stated, at CAT III 600 V. This shelf's buying tip insists the category and the voltage are one specification rather than two, and this is the only listing on this shelf that gives them as one: CAT III AND 600 V, in the same phrase | DC ONLY, and the listing says so outright: "DC current (Can not for AC current)". No ampere figure is published. That is the limit of the instrument and it is stated in a bullet rather than buried — which is more than can be said for a good deal of this shelf | AC and DC voltage, DC current, resistance, continuity and diode measurement, with a DATA HOLD and a backlight. No resistance ceiling is published — the MM325 states 2 MΩ, the MM450 50 MΩ, the published coczow 20 MΩ. A rotary switch sets the range, and the listing asks you to check it is in the right position, so the ranging is manual |
| AstroAI Digital multimeter with ceramic fuses | $15 | AC/DC voltage | DC current | resistance · diode |
| coczow CAT III digital multimeter | $25 | 600 V AC/DC | 10 A | auto power-off |
Details checked on October 8, 2026.
Car and bench electrical diagnosis, where the circuits are 12 V and the sensors must not be loaded by the meter
Listed because the accessory names this instrument itself.
Specifications: the manufacturer sheet for measuring instruments and the matching Amazon product page. Prices and availability: Keepa. Every figure on this page names its source.
AC/DC voltage · DC current · resistance · diode · double ceramic fuse
A compact meter whose distinguishing specification is its protection: a double ceramic fuse stated as flame-retardant, plus a silicone sleeve, at fourteen euros.
Best for: A first multimeter for household and hobby electronics, chosen for its fusing rather than its features.
≈ $15
True RMS · 6000 counts · 600 V · temperature, capacitance and frequency
A true-RMS meter with 6000-count resolution and a wide function list — voltage, current, resistance, temperature, diode, continuity, capacitance and frequency — with probe caps included.
Best for: Household and light installation work where waveforms are not clean and the reading has to be right.
CAT III stated · 600 V AC/DC · 10 A · 20 MΩ · auto power-off
The only multimeter in this hub whose listing states a measurement category. It also gives its ranges plainly: 600 V AC and DC, 10 A, 20 MΩ.
Best for: Household and installation fault-finding where knowing the category matters more than the feature list.
≈ $25
