1. Introduction
Thank you for choosing the SECRUI Wireless Doorbell. This manual provides detailed instructions for the installation, operation, and maintenance of your new doorbell system. Please read this manual carefully before use and retain it for future reference.
2. Product Overview
2.1 Components
- 1 x Wireless Doorbell Receiver
- 1 x Wireless Doorbell Transmitter (Button)
- 1 x CR2032 Battery (pre-installed in transmitter)
- Mounting Hardware (Screws, Wall Anchors, 3M Adhesive Tape)
- User Manual
2.2 Key Features
- Wireless Operation: Enjoy a stable connection with a long range of up to 300 meters (1000 feet) in open areas.
- IP55 Waterproof Transmitter: Designed for outdoor use, resistant to dust and water splashes, operating reliably in temperatures from -20°C to 60°C.
- Customizable Chimes: Choose from 58 distinct melodies.
- Adjustable Volume: 5 levels of volume control, ranging from 0 dB (mute) to 120 dB.
- Memory Function: Retains your last selected melody and volume level even after power loss.
- LED Indicator: Visual alert for visitors, useful for noisy environments or hearing-impaired users.
- Long Battery Life: Transmitter battery (CR2032) lasts up to 3 years.
- Expandable System: Easily pair additional receivers (up to 20) with one transmitter, or multiple transmitters with one receiver.

Image: Transmitter features including IP55 waterproof rating, temperature resistance, and battery life.

Image: Receiver highlighting 58 melodies, 5 volume levels, and LED indicator.
3. Specifications
| Model Number | M520+f55 |
| Brand | SECRUI |
| Dimensions (L x W x H) | 6.5 x 2 x 6.5 cm (Transmitter); Receiver dimensions not specified, but compact. |
| Weight | 110 grams (total package weight) |
| Transmitter Battery | 1 x CR2032 (included) |
| Receiver Power | AC Plug-in (EU plug type) |
| Waterproof Rating | IP55 (Transmitter) |
| Operating Temperature | -20°C to 60°C |
| Wireless Range | Up to 300 meters (1000 feet) in open air |
| Melodies | 58 options |
| Volume Levels | 5 levels (0-120 dB) |
| Material | ABS |
4. Setup and Installation
4.1 Receiver Installation
- Unpack the receiver unit.
- Plug the receiver into a standard wall socket in your desired location. Ensure the socket is easily accessible and not obstructed.
- The receiver will light up and emit a default chime, indicating it is powered on and ready.

Image: Receiver plugged into a wall socket and transmitter mounted on a door.
4.2 Transmitter (Button) Installation
The transmitter can be installed using either the provided 3M adhesive tape or screws.
Method 1: 3M Adhesive Tape
- Clean the desired mounting surface thoroughly to ensure it is dry and free of dust or grease.
- Peel off one side of the protective film from the 3M adhesive tape and attach it to the back of the transmitter.
- Peel off the other side of the protective film and firmly press the transmitter onto the cleaned surface for at least 30 seconds.
Method 2: Screw Mounting
- Open the back cover of the transmitter using a small screwdriver or prying tool.
- Mark the positions for drilling holes on the wall using the back cover as a template.
- Drill two holes, insert the wall anchors, and then secure the back cover to the wall with the provided screws.
- Snap the transmitter unit back onto its secured back cover.

Image: Detailed steps for adhesive and screw mounting of the transmitter.

Image: A hand pressing the doorbell button after installation.
5. Operating Instructions
5.1 Changing Melodies
On the side of the receiver, locate the "Melody Selection" button (often indicated by a music note icon). Press this button repeatedly to cycle through the 58 available melodies. The receiver will play each melody as you press the button. Stop pressing when you hear your desired melody.
5.2 Adjusting Volume
On the side of the receiver, locate the "Volume Control" button (often indicated by a speaker icon). Press this button to cycle through the 5 volume levels (0-120 dB). The receiver will play a short sound at each level to indicate the current volume. Select the level that suits your preference.
5.3 Pairing Additional Units (Optional)
If you have purchased additional SECRUI transmitters or receivers, you can pair them with your existing system:
- Plug in the receiver you wish to pair.
- Press and hold the "Volume Control" button on the receiver for approximately 5 seconds until you hear a "ding-dong" sound and the LED indicator flashes rapidly. This indicates pairing mode.
- Within 10 seconds, press the button on the transmitter you wish to pair. The receiver will chime, confirming successful pairing.
- Repeat for any additional transmitters or receivers.
Note: The system supports up to 20 transmitters per receiver and one transmitter can control multiple receivers.
6. Maintenance
6.1 Cleaning
Wipe the doorbell units with a soft, dry cloth. Do not use abrasive cleaners or solvents, as these may damage the surface or internal components. The transmitter is IP55 waterproof, but avoid submerging it in water.
6.2 Transmitter Battery Replacement
When the transmitter button's LED indicator no longer lights up or the range decreases significantly, it's time to replace the battery.
- Carefully open the back cover of the transmitter using a small screwdriver.
- Remove the old CR2032 battery.
- Insert a new CR2032 battery with the positive (+) side facing up.
- Close the back cover securely, ensuring the waterproof seal is properly seated.
Note: Dispose of old batteries responsibly according to local regulations.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Receiver does not chime. |
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| Short operating range. |
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| False alarms. |
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8. Warranty and Support
8.1 Manufacturer's Warranty
This SECRUI Wireless Doorbell is covered by an 18-month manufacturer's warranty from the date of purchase. This warranty covers defects in materials and workmanship under normal use. It does not cover damage caused by misuse, accident, unauthorized modification, or improper installation.
8.2 Customer Support
If you encounter any issues or have questions regarding your SECRUI Wireless Doorbell, please contact our customer support team. For the fastest service, please have your model number (M520+f55) and purchase details ready.
- Email: support@secrui.com (Example, actual email not provided)
- Website: Visit the SECRUI Store on Amazon
9. Video Demonstration
Video: A short demonstration of the SECRUI Wireless Doorbell, showing its components, easy installation, and adjustable features like melodies and volume.





