The YL-333 Magnetic Anti-Theft Alarm for Window/Door is a complete ready-to-use security alarm powered by 2 x AAA batteries at 3V, producing a 90-100dB loud buzzer alert, installed using included adhesive tape. Unlike the bare KY-025 reed switch sensor module covered separately, this magnetic door alarm is a finished consumer product — combining the same magnetic reed switch principle with a battery, buzzer, and casing into a self-contained unit requiring no wiring, soldering, or programming whatsoever.
The magnetic door security alarm comes as a two-piece set — one half containing a magnet, the other containing the reed switch and buzzer electronics — mounted with adhesive tape on the door/window frame and the door/window leaf respectively, positioned close enough that the magnet keeps the internal switch closed when the door is shut. As a security alarm, when the door or window opens, the magnet moves away, breaking the magnetic field and triggering the yl333 magnetic alarm’s loud buzzer instantly. This magnetic alarm system requires only correct adhesive placement for setup, no electrical knowledge needed.
this yl 333 magnetic anti theft alarm produces only a local loud sound alert — it doesn’t connect to a phone app, SMS notification, or central monitoring system, so it’s best as a standalone deterrent rather than a remote-monitored security solution.
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Features:
- Two-piece magnet and sensor design for door/window installation
- 90-100dB loud buzzer alert triggers when magnetic contact breaks
- No wiring, soldering, or programming — fully ready to use
- Adhesive tape mounting for quick tool-free installation
- 2 x AAA battery powered for long standalone operation
Technical specifications:
 Applications:
- YL-333 Alarm used for home window door theft deterrent build
- College project uses magnetic door alarm for security demo
- Shop uses magnetic door security alarm for India retail entry alert
- Apartment uses security alarm for simple no-wiring door protection
- DIY home security uses yl333 magnetic alarm for window monitoring
Package includes:
- 1 x YL-333 Magnetic Anti-Theft Alarm
Aarohi Grewal –
Very happy with purchase
Saisha Kapoor –
Delivery tracked properly
Shaurya Choudhury –
Reliable magnetic door and window security monitoring, making it ideal for DIY projects, home safety systems, and automation applications
Kian Mukherjee –
Professional packing ensured safe delivery, while the support team was helpful with product-related queries and installation guidance
Vivaan Reddy –
Suitable for door alarm systems, window security monitoring, and educational electronics projects requiring dependable magnetic detection and alarm functionality.