--- product_id: 136852986 title: "Twidec/M12 Approach Sensor Inductive Proximity Switch NPN NO DC 6-36V, 4mm Detecting Distance LJ12A3-4-Z/BX" price: "6202 Ft" currency: HUF in_stock: true reviews_count: 8 url: https://www.desertcart.hu/products/136852986-twidec-m12-approach-sensor-inductive-proximity-switch-npn-no-dc store_origin: HU region: Hungary --- # DC 6-36V wide voltage range 4mm precise detecting distance 300mA current output capacity Twidec/M12 Approach Sensor Inductive Proximity Switch NPN NO DC 6-36V, 4mm Detecting Distance LJ12A3-4-Z/BX **Price:** 6202 Ft **Availability:** βœ… In Stock ## Summary > πŸ” Detect with precision, control with confidence! ## Quick Answers - **What is this?** Twidec/M12 Approach Sensor Inductive Proximity Switch NPN NO DC 6-36V, 4mm Detecting Distance LJ12A3-4-Z/BX - **How much does it cost?** 6202 Ft with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hu](https://www.desertcart.hu/products/136852986-twidec-m12-approach-sensor-inductive-proximity-switch-npn-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 - β€’ **Precision Detection:** 4mm sensing range delivers accurate, non-contact detection for iron objects, perfect for automated control systems. - β€’ **Robust Output Current:** Supports up to 300mA output current, providing reliable signal strength for consistent machine performance. - β€’ **Compact & Durable Design:** Sleek 12mm cylindrical sensor crafted from plastic and alloy materials, built to withstand demanding industrial environments. - β€’ **Plug-and-Play Integration:** Equipped with a 1.2m cable and standard NPN NO output, enabling quick installation and seamless compatibility with existing control units. - β€’ **Wide Voltage Compatibility:** Operates seamlessly from 6 to 36 volts DC, ensuring versatile integration across diverse industrial setups. ## Overview The Twidec/M12 Inductive Proximity Switch is a compact, industrial-grade sensor designed for precise, non-contact detection of iron objects within a 4mm range. Operating on a broad DC voltage spectrum (6-36V) and delivering up to 300mA output current, it ensures reliable performance in automation, manufacturing, and control applications. Its durable plastic and alloy construction, combined with a convenient 1.2m cable and NPN NO output, makes it an essential component for professionals seeking dependable and easy-to-integrate sensing solutions. ## 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: Using this sensor with a Monoprice Select V2 - I purchased this inductive sensor as a bed leveling sensor for my Monoprice Select V2. After upgrading the Marlin firmware and making a few changes in the Configuration.h tab I got the sensor to work. I connected the sensor to an Arduino Uno powered with a 9v battery. The sensor is being powered with the input voltage (9v) which gives the sensor enough of a sensing distance that the sensor could be places slightly higher than the hotend nozzle (.12mm). This setup supplied enough voltage to the sensor to get it to detect the aluminum print bed. The higher the input voltage to the sensor the greater the detection distance. I will be trying a voltage divider where the sensor connects to the the Arduino Uno so I can get a higher voltage through the sensor and a lower voltage to the arduino and MKS Gen L board. Review: Garbage, was a dud, didn't work. - TLDR, Doesnt work as expected. It doesnt drop voltage fully, it leaks voltage. I am not new to 3D printers, been building them and using them for over 5 years. Lately my 4 yr old Z probe sensor quit in my CoreXY, so i got this as a replacement. After wiring this sensor trusting it will work, it didnt and crashed my bed. The 10k ohm internal resistance seems ok, being NO, the output voltage seems ok, but when triggered it leaks voltage and wont trigger the end stop. Pulled an old LJ18A3 i had in a drawer and that one works fine as expected. Bad batch, not happy it didnt work. ## 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/BX;Theory : Inductive Sensor;Output Type: NPN 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 | 4.2 out of 5 stars 58 Reviews | ## Images ![Twidec/M12 Approach Sensor Inductive Proximity Switch NPN NO DC 6-36V, 4mm Detecting Distance LJ12A3-4-Z/BX - Image 1](https://m.media-amazon.com/images/I/71-zuSIU4jL.jpg) ## Available Options This product comes in different **Size** options. ## 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 ### ⭐⭐⭐⭐⭐ Using this sensor with a Monoprice Select V2 *by D***L on May 8, 2019* I purchased this inductive sensor as a bed leveling sensor for my Monoprice Select V2. After upgrading the Marlin firmware and making a few changes in the Configuration.h tab I got the sensor to work. I connected the sensor to an Arduino Uno powered with a 9v battery. The sensor is being powered with the input voltage (9v) which gives the sensor enough of a sensing distance that the sensor could be places slightly higher than the hotend nozzle (.12mm). This setup supplied enough voltage to the sensor to get it to detect the aluminum print bed. The higher the input voltage to the sensor the greater the detection distance. I will be trying a voltage divider where the sensor connects to the the Arduino Uno so I can get a higher voltage through the sensor and a lower voltage to the arduino and MKS Gen L board. ### ⭐ Garbage, was a dud, didn't work. *by F***A on March 21, 2022* TLDR, Doesnt work as expected. It doesnt drop voltage fully, it leaks voltage. I am not new to 3D printers, been building them and using them for over 5 years. Lately my 4 yr old Z probe sensor quit in my CoreXY, so i got this as a replacement. After wiring this sensor trusting it will work, it didnt and crashed my bed. The 10k ohm internal resistance seems ok, being NO, the output voltage seems ok, but when triggered it leaks voltage and wont trigger the end stop. Pulled an old LJ18A3 i had in a drawer and that one works fine as expected. Bad batch, not happy it didnt work. ### ⭐⭐⭐ 2mm detection only. *by F***O on August 3, 2020* Installed it the moment I got it but what a let down. I cut the wires to fit my printer and now I can’t return it. I needed it to detect 4mm or higher but this only detects 2mm. DO NOT BUY if your printer has a removable non-metal build surface like my printer does. ## Frequently Bought Together - Twidec/M12 Approach Sensor Inductive Proximity Switch NPN NO DC 6-36V, 4mm Detecting Distance LJ12A3-4-Z/BX - BRINGSMART 12V 23rpm DC Worm Gear Motor 8kg.cm Low Speed Mini Turbine Worm Reducer Electric Motor Self-Locking for Toys (JGY-370 12V 23rpm) - TMEZON 12 Volt 2A Power Adapter Supply AC to DC 2.1mm X 5.5mm Plug 12v 2 Amp Wall Plug Extra Long 8 Foot Cord LED Strip Module Light --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hu/products/136852986-twidec-m12-approach-sensor-inductive-proximity-switch-npn-no-dc](https://www.desertcart.hu/products/136852986-twidec-m12-approach-sensor-inductive-proximity-switch-npn-no-dc) --- *Product available on Desertcart Hungary* *Store origin: HU* *Last updated: 2026-05-08*