Extech MA440
#4 in AC onlyFull review
A plain true-RMS AC clamp for electricians and technicians who only need current, voltage and resistance.
Amazon $66.99$66.99
The Extech MA440 and the Klein Tools CL120 are evenly matched, rated 3.1 and 3.0. The Extech MA440 leads on features. The Klein Tools CL120 wins on jaw opening. The Klein Tools CL120 costs $3.10 less ($63.89 vs $66.99).
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.
Klein Tools CL120
#7 in AC onlyFull review
An inexpensive AC clamp for homeowners and apprentices who need occasional current and voltage checks.
Amazon $63.89$63.89
Which should you buy?
- Choose the Extech MA440 for features (true RMS, non-contact voltage vs non-contact voltage).
- Choose the Klein Tools CL120 for jaw opening (41 mm jaw vs 30 mm jaw).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every AC only clamp meter; a clear win is highlighted. How we rank explains each one.
| Factor weight | Extech MA440 | Klein Tools CL120 |
|---|---|---|
| Overall rating | 3.1/5 | 3.0/5 |
| Current range 15% | 46 400 A through the jaw | 46 400 A through the jaw |
| DC current 15% | 0 no DC current | 0 no DC current |
| Safety rating 20% | 55 CAT III 600 V | 55 CAT III 600 V |
| Features 15% | 35 true RMS, non-contact voltage | 10 non-contact voltage |
| Accuracy 10% | 67 2% of reading | 67 2% of reading |
| Jaw opening 5% | 33 30 mm jaw | 70 41 mm jaw |
| Warranty 10% | 50 2-year warranty | 50 2-year warranty |
| Price 10% | 87 $66.99 | 89 $63.89 |
Specifications
| Extech MA440 | Klein Tools CL120 | |
|---|---|---|
| Measurement | ||
| AC current (jaw) | 400 A | 400 A |
| DC current (jaw) | No | No |
| Voltage | - | 600 V |
| Current accuracy | 2% of reading | 2% of reading |
| Jaw opening | 30 mm | 41 mm |
| Safety | ||
| CAT rating | CAT III 600 V | CAT III 600 V |
| Features | ||
| True RMS | Yes | No |
| Inrush | No | No |
| LoZ mode | No | No |
| Non-contact voltage | Yes | Yes |
| Low-pass filter | No | No |
| Temperature | No | No |
| Phone app | No | No |
| Build | ||
| Weight | 265 g | 313 g |
| Warranty | 2 years | 2 years |