


About Klein Tools
As an American manufacturer of hand tools for more than 160 years, Klein Tools makes premium-quality, professional-grade tools that deliver performance, durability and precision. Our team continues to put six generations of expertise into each tool by using the highest quality materials and superior workmanship.
Klein Tools doesn't just make great products, we make great products that stand up to the demands of the professionals who use them every day … Since 1857.
Digital AC/DC Voltage Tester, 12-240V AC, 1.5-24V DC, LED Illumination, DC Polarity, Auto Off,CAT III 250V-Class 2- Double Insulation, IP41 Dust,Water Resistant
Klein Tools ET40 is an Electronic AC/DC Voltage Tester. It measures AC voltages from 12V to 240V and DC voltages as low as 1.5V up to 24V. Tester also indicates positive and negative DC polarity.
- Voltage Tester for AC voltages from 12V to 240V AC at four useful levels aligned with commonly used residential voltages
- Tests DC voltages from 1.5V to greater than 17 to 24V at four useful levels aligned with commonly used DC voltages
- Bright LEDs illuminate to indicate the type and level of voltage detected
- Built to withstand a 9.8-Foot (3 m) drop
- Indicates polarity when measuring DC voltages
- Powers off automatically after approximately 2 minutes of non-use to conserve battery life
- CAT III 250V, Class 2, Double insulation
- Ingress protection IP41 dust and water resistant
FEATURES

Tests voltages for AC at four useful levels: from 12V to 240V AC

Tests voltages for DC at 1.5V to >17- 24V, at four useful levels

Bright LEDs indicate the type and level of voltage detected
![]() Klein Tools 5139C Zipper Bag, Camouflage Cordura Nylon Tool Pouch with Heavy-... | ![]() Klein Tools 5139PAD Zipper Bag, Cordura Nylon Tool Pouch with Layered Padding... | ![]() Klein Tools ET910 USB Power Meter and Tester, USB-A Digital Meter for Voltage... | ![]() Klein Tools ET250 Voltage Meter, AC/DC Tester, Digital Multimeter, Low Voltag... | ![]() Klein Tools ET920 USB Power Meter, USB-A and USB-C Digital Meter for Voltage,... | ![]() Klein Tools ET310 AC Circuit Breaker Finder, Electric and Voltage Tester with... | |
|---|---|---|---|---|---|---|
| Customer Reviews | — | — | — | — | — | — |
| Price | — | — | — | — | — | — |
| Mfg. No. | 5139C | 5139PAD | ET910 | ET250 | ET920 | ET310 |
| Description | Klein Tools 5139C Zipper Bag, Camouflage Cordura Nylon Tool Pouch with Heavy-... | Klein Tools 5139PAD Zipper Bag, Cordura Nylon Tool Pouch with Layered Padding... | Klein Tools ET910 USB Power Meter and Tester, USB-A Digital Meter for Voltage... | Klein Tools ET250 Voltage Meter, AC/DC Tester, Digital Multimeter, Low Voltag... | Klein Tools ET920 USB Power Meter, USB-A and USB-C Digital Meter for Voltage,... | Klein Tools ET310 AC Circuit Breaker Finder, Electric and Voltage Tester with... |

Digital AC/DC Voltage Tester, 12-240V AC, 1.5-24V DC, LED Illumination, DC Polarity, Auto Off,CAT III 250V-Class 2- Double Insulation, IP41 Dust,Water Resistant

About Klein Tools
As an American manufacturer of hand tools for more than 160 years, Klein Tools makes premium-quality, professional-grade tools that deliver performance, durability and precision. Our team continues to put six generations of expertise into each tool by using the highest quality materials and superior workmanship.
Klein Tools doesn't just make great products, we make great products that stand up to the demands of the professionals who use them every day … Since 1857.

Klein Tools ET40 is an Electronic AC/DC Voltage Tester. It measures AC voltages from 12V to 240V and DC voltages as low as 1.5V up to 24V. Tester also indicates positive and negative DC polarity.
- Voltage Tester for AC voltages from 12V to 240V AC at four useful levels aligned with commonly used residential voltages
- Tests DC voltages from 1.5V to greater than 17 to 24V at four useful levels aligned with commonly used DC voltages
- Bright LEDs illuminate to indicate the type and level of voltage detected
- Built to withstand a 9.8-Foot (3 m) drop
- Indicates polarity when measuring DC voltages
- Powers off automatically after approximately 2 minutes of non-use to conserve battery life
- CAT III 250V, Class 2, Double insulation
- Ingress protection IP41 dust and water resistant
FEATURES

Tests voltages for AC at four useful levels: from 12V to 240V AC

Tests voltages for DC at 1.5V to >17- 24V, at four useful levels

Bright LEDs indicate the type and level of voltage detected
![]() Klein Tools 5139C Zipper Bag, Camouflage Cordura Nylon Tool Pouch with Heavy-... | ![]() Klein Tools 5139PAD Zipper Bag, Cordura Nylon Tool Pouch with Layered Padding... | ![]() Klein Tools ET910 USB Power Meter and Tester, USB-A Digital Meter for Voltage... | ![]() Klein Tools ET250 Voltage Meter, AC/DC Tester, Digital Multimeter, Low Voltag... | ![]() Klein Tools ET920 USB Power Meter, USB-A and USB-C Digital Meter for Voltage,... | ![]() Klein Tools ET310 AC Circuit Breaker Finder, Electric and Voltage Tester with... | |
|---|---|---|---|---|---|---|
| Customer Reviews | — | — | — | — | — | — |
| Price | — | — | — | — | — | — |
| Mfg. No. | 5139C | 5139PAD | ET910 | ET250 | ET920 | ET310 |
| Description | Klein Tools 5139C Zipper Bag, Camouflage Cordura Nylon Tool Pouch with Heavy-... | Klein Tools 5139PAD Zipper Bag, Cordura Nylon Tool Pouch with Layered Padding... | Klein Tools ET910 USB Power Meter and Tester, USB-A Digital Meter for Voltage... | Klein Tools ET250 Voltage Meter, AC/DC Tester, Digital Multimeter, Low Voltag... | Klein Tools ET920 USB Power Meter, USB-A and USB-C Digital Meter for Voltage,... | Klein Tools ET310 AC Circuit Breaker Finder, Electric and Voltage Tester with... |





















