The Klein Tools ET40 is a digital AC/DC voltage tester with an analog LED display that tests four common AC voltage levels from 12 to 240V and four DC voltage levels from 1.5 to 24V. Built-in test lead holders are spaced for tamper-resistant US outlets and double as a convenient storage feature. Rated CAT III 250V with IP41 environmental protection and 9.8-foot drop resistance. Runs on two included AAA batteries. The ET40 suits residential and light commercial work requiring quick go/no-go voltage checks across AC and DC circuits. Backed by Klein Tools' 1-year limited warranty.
What's the difference between the ET40 and ET60?
ET40 covers 12–240V AC and 1.5–24V DC with an analog LED display and requires 2 AAA batteries. The ET60 extends to 600V AC/DC, is completely self-powered (no batteries), carries a higher CAT IV 600V rating, and is IP54 splash-resistant. Choose ET40 for general residential work; ET60 for wider range and battery-free operation.
Does the ET40 require batteries?
Yes — it uses 2 AAA batteries to power the analog LED display. Unlike the ET60, which draws power from the circuit under test, the ET40 needs working batteries to operate.
Can the ET40 test DC circuits?
Yes — it measures 1.5–24V DC, covering AA/AAA/9V batteries, automotive electronics, and low-voltage DC control wiring such as thermostats and irrigation controllers.
Is the ET40 suitable for 240V circuits?
Yes — the 12–240V AC range covers standard 120V and 240V residential circuits. For 277V or 480V commercial/industrial circuits, use the ET60 instead.
What does the analog LED bar display show?
The LED bar indicates voltage level in graduated steps rather than a precise numeric readout — sufficient for confirming presence of voltage and identifying approximate voltage zones. If you need exact voltage readings, step up to the ET250 or ET270.
What does IP41 protection mean?
IP41 means the tool is protected against solid objects larger than 1mm and dripping water falling vertically. It provides basic splash protection for typical job-site conditions, though it is less robust than the ET60's IP54 rating.
# Klein Tools® ET40 Digital AC/DC Voltage Tester, 12 to 240V AC, 1.5 to 24V DC **Model:** `ET40` **Brand:** Klein Tools **Category:** Voltage Tester > The Klein Tools ET40 is a digital AC/DC voltage tester with an analog LED display that tests four common AC voltage levels from 12 to 240V and four DC voltage levels from 1.5 to 24V. Built-in test lead holders are spaced for tamper-resistant US outlets and double as a convenient storage feature. Rated CAT III 250V with IP41 environmental protection and 9.8-foot drop resistance. Runs on two included AAA batteries. The ET40 suits residential and light commercial work requiring quick go/no-go voltage checks across AC and DC circuits. Backed by Klein Tools' 1-year limited warranty. ## Specifications | Attribute | Value | |---|---| | Product Type | Digital AC/DC Voltage Tester | | Voltage Range Ac | 12–240V AC | | Voltage Range Dc | 1.5–24V DC | | Safety Rating | CAT III 250V | | Ip Rating | IP41 | | Frequency | 50/60 Hz | | Display Type | Analog LED | | Battery Type | 2 × AAA | | Battery Required | Yes | | Drop Protection Ft | 9.8 | | Overall Length In | 5.24 | | Assembled Weight Oz | 2.3 | | Barcode (UPC) | 092644691836 | | Warranty | 1-year limited | ## What's Included - Tester - User manual - 2 × AAA batteries Source: https://www.jaspecs.com/klein-tools/voltage-tester/et40-klein-tools-digital-acdc-voltage-tester-12-240v-ac-15-24v-dc/