--- product_id: 248281967 title: "MC-31 Wired Surface-Mounted NC Magnetic Door Window Contact Sensor Alarm Reed Switch, White, Pack of 5 with 20 Screws" brand: "qwork" price: "420094₫" currency: VND in_stock: true reviews_count: 13 category: "Qwork" url: https://www.desertcart.vn/products/248281967-mc-31-wired-surface-mounted-nc-magnetic-door-window-contact store_origin: VN region: Vietnam --- # Normally Closed (NC) magnetic contact Pack of 5 with 20 screws included 8mm±1.8mm actuation distance MC-31 Wired Surface-Mounted NC Magnetic Door Window Contact Sensor Alarm Reed Switch, White, Pack of 5 with 20 Screws **Brand:** qwork **Price:** 420094₫ **Availability:** ✅ In Stock ## Summary > 🛡️ Lock in peace of mind with QWORK’s magnetic precision! ## Quick Answers - **What is this?** MC-31 Wired Surface-Mounted NC Magnetic Door Window Contact Sensor Alarm Reed Switch, White, Pack of 5 with 20 Screws by qwork - **How much does it cost?** 420094₫ with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.vn](https://www.desertcart.vn/products/248281967-mc-31-wired-surface-mounted-nc-magnetic-door-window-contact) ## Best For - qwork enthusiasts ## Why This Product - Trusted qwork brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Complete Installation Kit:** Five sensors plus 20 screws ensure a seamless, professional-grade setup right out of the box. - • **Precision Magnetic Sensing:** Reliable NC reed switch triggers instantly within 8mm±1.8mm for foolproof security. - • **Sleek Surface-Mount Design:** Low-profile white plastic casing blends effortlessly with modern doors and windows. - • **Durable & Weather-Resistant:** IP65 rating means these sensors stand strong against dust and moisture, perfect for any environment. - • **Versatile Security Application:** Ideal for doors, windows, cabinets—upgrade your smart home or office security with ease. ## Overview The QWORK MC-31 is a wired, surface-mounted magnetic door/window contact sensor featuring a normally closed reed switch with an 8mm±1.8mm actuation distance. Packaged in sets of five with 20 screws, it offers easy installation and reliable security for doors, windows, and cabinets. Its sleek white plastic design and IP65 rating ensure durability and discreet integration into any home or office environment. ## Description desertcart.com: QWORK MC-31 Wired Surface-Mounted NC Magnetic Door Window Contact Sensor Alarm Reed Switch, White, Pack of 5 with 20 Screws : Industrial & Scientific Review: Needed replacement magnetic contacts - When our lower level of the house was re-modeled, the contactor did not save the contacts from two door moldings for my Ring and Insteon sensors. I got these just for the contacts and they work fine for my Ring and Insteon open/close sensors. Review: Low cost perfect solution - Ok. Let’s face it that I know nothing about an alarm system. I have an ADT system and a construction worker accidentally broke this small sensor at my basement door. Well after 2 hours of waiting, 4 transfers, and horribly exasperating experience with ADT and so solution. I simply looked on the desertcart for something that looked similar to me and I found this part. The order arrived quickly, it was simple to attach, and it works perfectly. I’m still planning to change from ADT because it’s just terrible. ## Features - Product Information: Product name: Surface-mounted Magnetic Door Switch, Type: MC-31, Color: White, Material: Plastic - Specification: Contact Type: NC, Hole Dia.: 5.8mm, Actuation Distance: 8mm±18mm - Sizes: 64*12.*12mm and 64*20*12mm（L * W * H),pack of 5 with 20 screws. - NC Type: NC means normally closed. If the magnet is closed to this switch, the signal is conductive, otherwise, if the magnet is far away from this switch, the signal is disconnected. - Applications: It is suitable for magnetic windows, doors, cabinets etc. Ideal for door, window security. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B08FT91C1G | | Actuator Type | Magnetic | | Best Sellers Rank | #35,043 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #6 in Reed Switches | | Brand | QWORK | | Circuit Type | 1-way | | Color | White | | Connectivity Protocol | X-10 | | Connector Type | Screws | | Contact Material | Plastic | | Contact Type | Normally Closed | | Control Method | Touch | | Date First Available | August 13, 2020 | | International Protection Rating | IP65 | | Item Weight | 0.01 ounces | | Item model number | WD3811 | | Manufacturer | QWORK | | Mounting Type | Door Mount | | Number of Positions | 2 | | Operation Mode | automatic | | Package Dimensions | 5.43 x 4.49 x 0.63 inches | | Terminal | Screw | | Unit Count | 5.0 Count | ## Product Details - **Actuator Type:** Magnetic - **Brand:** QWORK - **Circuit Type:** 1-way - **Connector Type:** Screws - **Contact Type:** Normally Closed - **Material:** Plastic - **Mounting Type:** Door Mount - **Operation Mode:** automatic - **Switch Type:** Reed Switch - **Terminal:** Screw ## Images ![MC-31 Wired Surface-Mounted NC Magnetic Door Window Contact Sensor Alarm Reed Switch, White, Pack of 5 with 20 Screws - Image 1](https://m.media-amazon.com/images/I/61qIPlQMfwL.jpg) ## Questions & Answers **Q: how long is the leader wires?** A: The leads are about 6 inches long. **Q: Type of reed switch? Voltage/Current specs needed** A: The reed switch type is NC. No voltage/current required. **Q: Does this have an end of line (eol) resistor internally?** A: It is a simple reed switch with no resistor. **Q: Do these work with ADT** A: They shot ## Customer Reviews ### ⭐⭐⭐⭐⭐ Needed replacement magnetic contacts *by A***. on July 16, 2025* When our lower level of the house was re-modeled, the contactor did not save the contacts from two door moldings for my Ring and Insteon sensors. I got these just for the contacts and they work fine for my Ring and Insteon open/close sensors. ### ⭐⭐⭐⭐⭐ Low cost perfect solution *by S***N on August 10, 2023* Ok. Let’s face it that I know nothing about an alarm system. I have an ADT system and a construction worker accidentally broke this small sensor at my basement door. Well after 2 hours of waiting, 4 transfers, and horribly exasperating experience with ADT and so solution. I simply looked on the Amazon for something that looked similar to me and I found this part. The order arrived quickly, it was simple to attach, and it works perfectly. I’m still planning to change from ADT because it’s just terrible. ### ⭐⭐⭐⭐ Cheap but functional *by R***. on January 24, 2025* Cheaply made. Had them come apart while installing. Product does work well. ## Frequently Bought Together - QWORK MC-31 Wired Surface-Mounted NC Magnetic Door Window Contact Sensor Alarm Reed Switch, White, Pack of 5 with 20 Screws - HiLetgo 5V 4 Channel Relay Shield for UNO R3 Relay Shield Four Channel Relay Shield for UNO R3 - Arduino Uno Rev3 SMD Microcontroller Board [A000073] – ATmega328P, 16MHz, 32KB Flash, USB & PWM Support, Ideal for DIY Projects, STEM Learning, Robotics, and Prototyping --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.vn/products/248281967-mc-31-wired-surface-mounted-nc-magnetic-door-window-contact](https://www.desertcart.vn/products/248281967-mc-31-wired-surface-mounted-nc-magnetic-door-window-contact) --- *Product available on Desertcart Vietnam* *Store origin: VN* *Last updated: 2026-05-18*