Klein Tools CL445
#1 in AC onlyFull review
An HVAC clamp with inrush, flame-sensor microamps and a CAT IV rating at a mid-range price.
Amazon $94.85$94.85
The Klein Tools CL445 is the better clamp meter overall, rated 3.7 to 3.1. The Klein Tools CL445 leads on safety rating, features and DC current. The Extech MA440 wins on price. The Extech MA440 costs $27.86 less ($66.99 vs $94.85).
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.
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
Which should you buy?
- Choose the Klein Tools CL445 for safety rating (CAT IV 600 V / CAT III 750 V vs CAT III 600 V), features (true RMS, inrush, non-contact voltage, temperature, DC microamps vs true RMS, non-contact voltage) and DC current (DC microamps (600 uA) through the test leads only vs no DC current).
- Choose the Extech MA440 for price ($66.99 vs $94.85).
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 | Klein Tools CL445 | Extech MA440 |
|---|---|---|
| Overall rating | 3.7/5 | 3.1/5 |
| Current range 15% | 60 600 A through the jaw | 46 400 A through the jaw |
| DC current 15% | 25 DC microamps (600 uA) through the test leads only | 0 no DC current |
| Safety rating 20% | 100 CAT IV 600 V / CAT III 750 V | 55 CAT III 600 V |
| Features 15% | 65 true RMS, inrush, non-contact voltage, temperature, DC microamps | 35 true RMS, non-contact voltage |
| Accuracy 10% | 67 2% of reading | 67 2% of reading |
| Jaw opening 5% | 40 32 mm jaw | 33 30 mm jaw |
| Warranty 10% | 50 2-year warranty | 50 2-year warranty |
| Price 10% | 72 $94.85 | 87 $66.99 |
Specifications
| Klein Tools CL445 | Extech MA440 | |
|---|---|---|
| Measurement | ||
| AC current (jaw) | 600 A | 400 A |
| DC current (jaw) | No | No |
| DC microamps (leads) | 600 uA | - |
| Voltage | 750 V | - |
| Current accuracy | 2% of reading | 2% of reading |
| Jaw opening | 32 mm | 30 mm |
| Safety | ||
| CAT rating | CAT IV 600 V / CAT III 750 V | CAT III 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 | No |
| Phone app | No | No |
| Build | ||
| Weight | 357 g | 265 g |
| Warranty | 2 years | 2 years |