---
product_id: 650226288
title: "BT51A Wireless Motion Sensor Alarm with Intelligent Welcome Doorbell, Infrared Detector, Gate Alert Alarm, Remote Control, Easy Install for Daily Safety Protection"
price: "¥3699"
currency: JPY
in_stock: true
url: https://www.desertcart.jp/products/650226288-bt51a-wireless-motion-sensor-alarm-with-intelligent-welcome-doorbell-infrared
store_origin: JP
region: Japan
---

# 8m Infrared detection range 110dB adjustable alarm volume Easy no-tool installation BT51A Wireless Motion Sensor Alarm with Intelligent Welcome Doorbell, Infrared Detector, Gate Alert Alarm, Remote Control, Easy Install for Daily Safety Protection

**Price:** ¥3699
**Availability:** ✅ In Stock

## Summary

> 🚨 Stay ahead of every step with BT51A — your smart, silent guardian!

## Quick Answers

- **What is this?** BT51A Wireless Motion Sensor Alarm with Intelligent Welcome Doorbell, Infrared Detector, Gate Alert Alarm, Remote Control, Easy Install for Daily Safety Protection
- **How much does it cost?** ¥3699 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/650226288-bt51a-wireless-motion-sensor-alarm-with-intelligent-welcome-doorbell-infrared)

## 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

- • **Universal Application:** Ideal for entrances, offices, shops, and apartments—protect your space with style and ease.
- • **Customizable Alarm Volume:** Four volume levels up to 110dB let you tailor alerts to your environment and peace of mind.
- • **Effortless Setup in Minutes:** No drills or wires—mount on any surface with included double-sided tape or place on a table.
- • **Dual-Mode Security & Welcome:** Seamlessly switch between alert and greeting modes for versatile home or office use.
- • **Smart Infrared Motion Detection:** Sensitive sensor covers an 8-meter radius, catching every movement before it matters.

## Overview

The Blackt Electrotech BT51A is a compact, battery-powered wireless motion sensor alarm featuring an 8-meter infrared detection range and a powerful 110-decibel alarm with four adjustable volume settings. Designed for easy installation without tools, it doubles as an intelligent welcome doorbell and security alert system, making it perfect for diverse environments like homes, offices, and retail spaces.

## Description

Blackt Electrotech BT51A Wireless Motion Sensor Alarm with Intelligent Welcome Doorbell, Infrared Detector, Gate Alert Alarm, Remote Control, Easy Install for Daily Safety Protection : desertcart.in: Home Improvement

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0DBL4D681 |
| Audible Noise | 110 Decibels |
| Battery Description | Alkaline |
| Best Sellers Rank | #4,520 in Home Improvement ( See Top 100 in Home Improvement ) #8 in Motion Detectors |
| Brand | Blackt Electrotech |
| Built-In Media | Remote |
| Colour | white |
| Control Method | Remote |
| Country of Origin | China |
| Customer Reviews | 3.5 3.5 out of 5 stars (144) |
| Importer Contact Information | Blackt Electrotech |
| Item Type Name | Motion Sensor Detector Gate Alert Alarm |
| Item Weight | 150 Grams |
| Manufacturer | Blackt Electrotech |
| Maximum Range | 8 metres |
| Mfr Part Number | BT51A |
| Model Number | BT51A |
| Mounting Type | Wall Mount |
| Number of Items | 1 |
| Packer Contact Information | Blackt Electrotech |
| Power Source | Battery Powered |
| Sensor Technology | Infrared Sensor |
| Size | Small |
| Voltage | 5 Volts |

## Product Details

- **Battery Description:** Alkaline
- **Brand:** Blackt Electrotech
- **Colour:** white
- **Power Source:** Battery Powered
- **Voltage:** 5 Volts

## Images

![BT51A Wireless Motion Sensor Alarm with Intelligent Welcome Doorbell, Infrared Detector, Gate Alert Alarm, Remote Control, Easy Install for Daily Safety Protection - Image 1](https://m.media-amazon.com/images/I/51AJw6NMMVL.jpg)

## Questions & Answers

**Q: 1. What is the detection range of the motion sensor?**
A: The infrared sensor detects movement up to 8 meters away, making it ideal for entrances, hallways, gates, and walkways.

**Q: 2. Can this device work as both an alarm and a doorbell?**
A: Yes, it features 2-in-1 functionality with security alarm mode and welcome/chime mode for visitors and customers.

**Q: 3. How loud is the alarm?**
A: The alarm can reach up to 110dB and offers multiple volume levels, including silent mode, to suit different environments.

**Q: 4. Where can I install this motion alarm?**
A: It is suitable for homes, offices, shops, hotels, apartments, gates, reception areas, and other indoor entry points.

**Q: 5. Is installation complicated?**
A: No, installation is quick and easy. You can place it on a flat surface or mount it using double-sided adhesive tape.

## Frequently Bought Together

- Blackt Electrotech BT51A Wireless Motion Sensor Alarm with Intelligent Welcome Doorbell, Infrared Detector, Gate Alert Alarm, Remote Control, Easy Install for Daily Safety Protection
- Panasonic 9 Watt Motion Sensor Led B22D Bulb for Home with 3 Mtr Radius Sensor Area,Auto Off After 15 Sec Comes with 30000 Bh Life and 1 Yr Warranty

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**Shop now:** [https://www.desertcart.jp/products/650226288-bt51a-wireless-motion-sensor-alarm-with-intelligent-welcome-doorbell-infrared](https://www.desertcart.jp/products/650226288-bt51a-wireless-motion-sensor-alarm-with-intelligent-welcome-doorbell-infrared)

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-09-08*