Extech EX655
#2 in AC/DCFull review
A well-equipped AC/DC clamp with a three-year warranty, for HVAC and maintenance technicians.
Amazon $173.50$173.50
The Extech EX655 is the better clamp meter overall, rated 3.7 to 3.3. The Extech EX655 leads on safety rating and features. The UNI-T UT204R wins on price. The UNI-T UT204R costs $97.01 less ($76.49 vs $173.50).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
UNI-T UT204R
#9 in AC/DCFull review
A low-cost AC/DC clamp for car, solar and household work where a high safety rating isn’t needed.
Amazon $76.49$76.49
Which should you buy?
- Choose the Extech EX655 for safety rating (CAT III 600 V / CAT II 1,000 V vs CAT III 300 V / CAT II 600 V) and features (true RMS, inrush, non-contact voltage, temperature vs true RMS, non-contact voltage, temperature).
- Choose the UNI-T UT204R for price ($76.49 vs $173.50).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every AC/DC clamp meter; a clear win is highlighted. How we rank explains each one.
| Factor weight | Extech EX655 | UNI-T UT204R |
|---|---|---|
| Overall rating | 3.7/5 | 3.3/5 |
| Current range 15% | 60 600 A through the jaw | 60 600 A through the jaw |
| DC current 15% | 100 DC current to 600 A through the jaw | 100 DC current to 600 A through the jaw |
| Safety rating 20% | 55 CAT III 600 V / CAT II 1,000 V | 25 CAT III 300 V / CAT II 600 V |
| Features 15% | 60 true RMS, inrush, non-contact voltage, temperature | 45 true RMS, non-contact voltage, temperature |
| Accuracy 10% | 33 2.5% of reading | 50 current accuracy not published (neutral score used) |
| Jaw opening 5% | 33 30 mm jaw | 27 28 mm jaw |
| Warranty 10% | 100 3-year warranty | 0 warranty not published, scored as none |
| Price 10% | 46 $173.50 | 82 $76.49 |
Specifications
| Extech EX655 | UNI-T UT204R | |
|---|---|---|
| Measurement | ||
| AC current (jaw) | 600 A | 600 A |
| DC current (jaw) | 600 A | 600 A |
| Voltage | 1,000 V | 600 V |
| Current accuracy | 2.5% of reading | - |
| Jaw opening | 30 mm | 28 mm |
| Safety | ||
| CAT rating | CAT III 600 V / CAT II 1,000 V | CAT III 300 V / CAT II 600 V |
| Features | ||
| True RMS | Yes | Yes |
| Inrush | Yes | No |
| LoZ mode | No | No |
| Non-contact voltage | Yes | Yes |
| Low-pass filter | No | No |
| Temperature | Yes | Yes |
| Phone app | No | No |
| Build | ||
| Weight | 265 g | 235 g |
| Warranty | 3 years | - |