---
product_id: 140659521
title: "Twidec/M12 Approach Sensor Inductive Proximity Switch PNP NO DC 6-36V, 4mm Detecting Distance LJ12A3-4-Z/BY"
price: "$20.37"
currency: USD
in_stock: true
reviews_count: 8
url: https://www.desertcart.us/products/140659521-twidec-m12-approach-sensor-inductive-proximity-switch-pnp-no-dc
store_origin: US
region: United States of America
---

# DC 6-36V wide voltage range 4mm precise detecting distance 300mA reliable current output Twidec/M12 Approach Sensor Inductive Proximity Switch PNP NO DC 6-36V, 4mm Detecting Distance LJ12A3-4-Z/BY

**Price:** $20.37
**Availability:** ✅ In Stock

## Summary

> 🔍 Detect with precision, control with confidence.

## Quick Answers

- **What is this?** Twidec/M12 Approach Sensor Inductive Proximity Switch PNP NO DC 6-36V, 4mm Detecting Distance LJ12A3-4-Z/BY
- **How much does it cost?** $20.37 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/140659521-twidec-m12-approach-sensor-inductive-proximity-switch-pnp-no-dc)

## Best For

- Customers looking for quality international products

## Why This Product

- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Precision Detection at 4mm:** Pinpoint accuracy ensures your machinery reacts instantly to metal targets, minimizing downtime.
- • **Robust Voltage Flexibility:** Operates smoothly across a broad 6-36V DC range, adapting to diverse power setups without a hitch.
- • **Compact & Lightweight Design:** Sleek 12mm diameter cylinder weighing just 44g, perfect for tight spaces and easy installation.
- • **Seamless Automation Integration:** Effortlessly fits into your industrial control systems with PNP NO output for clean, reliable switching.
- • **Durable Build for Industrial Use:** Crafted from plastic and alloy materials to withstand demanding environments and ensure long-term reliability.

## Overview

The Twidec/M12 Inductive Proximity Switch LJ12A3-4-Z/BY is a compact, high-performance sensor designed for non-contact metal detection within a 4mm range. Featuring a wide DC 6-36V operating voltage and a robust 300mA current output, it integrates seamlessly into automated industrial systems. Its durable plastic and alloy construction ensures reliability in demanding environments, making it a trusted choice for professionals seeking precision and efficiency in machine control.

## Description

When proximity switch is close to some target object, it will send out control signal. It is widely used in machine, paper making, light industry for limiting station, orientation taking count, speeding trial ect. It is a component widely used in automatic control industry for detecting, controlling, and noncontact switching.

Review: Well - Good
Review: Works with Ender 3 + some external components - Like - light weight ~ 45g, flexible wire, repeatable , reasonable price. M48 P9 test Mean: -0.110833 Min: -0.113 Max: -0.108 Range: 0.005 Standard Deviation: 0.001667 I used the Ender 3 24V as power source. I chose the PNP model so the output is 24V. I used a voltage divider ( 4.7K and 1K ) to reduce the voltage. Only two issues - You need a metal build surface , I use PEI on spring steel, You need to make a voltage divider to connect it to the Z_End_Stop on the ENDER 3 control board.

## Features

- Product Name：Inductive Proximity Switch; Wire Type : DC 3 Wire Type (Black, Brown, Blue);Switch Appearance Type : Cylinder Type
- Supply Voltage : DC 6-36V;Current Output : 300mA;Detect Object : Iron
- Model: LJ12A3-4-Z/BY;Theory : Inductive Sensor;Output Type: PNP NO;Diameter of Column Sensor: 12mm;Detecting Distance : 4mm
- Total Size: 6.2 x 2cm/2.4'' x 0.8'' (L*Max. Dia); Cable Length: 1.2m/47'';Net Weight :44g
- External Material : Plastic, Alloy;Package Content : 1 x Inductive Proximity Switch

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Customer Reviews | 4.5 out of 5 stars 80 Reviews |

## Images

![Twidec/M12 Approach Sensor Inductive Proximity Switch PNP NO DC 6-36V, 4mm Detecting Distance LJ12A3-4-Z/BY - Image 1](https://m.media-amazon.com/images/I/71-zuSIU4jL.jpg)

## Questions & Answers

**Q: used for geeetech A10**
A: Use Google, Facebook and other forums to determine how to wire this with your 3D printer.

**Q: will this detect brass?**
A: Yes,

**Q: Is this a Hall Effect sensor?**
A: ASIN:B07P1GKQRM This is a Hall effect sensor

**Q: Does "4mm" mean I have to place it exactly 4mm from the surface?**
A: 4mm is max distance that sensor will reliably react

## Customer Reviews

### ⭐⭐⭐⭐⭐ Well
*by F***E on June 22, 2025*

Good

### ⭐⭐⭐⭐⭐ Works with Ender 3 + some external components
*by S***M on July 13, 2020*

Like - light weight ~ 45g, flexible wire, repeatable , reasonable price. M48 P9 test Mean: -0.110833 Min: -0.113 Max: -0.108 Range: 0.005 Standard Deviation: 0.001667 I used the Ender 3 24V as power source. I chose the PNP model so the output is 24V. I used a voltage divider ( 4.7K and 1K ) to reduce the voltage. Only two issues - You need a metal build surface , I use PEI on spring steel, You need to make a voltage divider to connect it to the Z_End_Stop on the ENDER 3 control board.

### ⭐⭐⭐⭐⭐ Perfect
*by B***T on February 22, 2023*

Worked great. Allows enough current for a 12 volt automotive relay to work. Was able to fit in with a handmade bracket to the shift gate of the stock Can-Am X3 to allow for reverse lights to come on automatically when put in the reverse position.

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-07-07*