HENDUN Door Alarms When Opened with Remote, Door Bells Chimes, Door Security Sensor Pool Alarm for Kids Safety (2 Pack)
Quick take
The HENDUN door alarms are simple magnetic contact sensors with a remote to arm and disarm, designed for quick “notice me when a door or gate opens” coverage. They are best for families who want loud, immediate alerts for exterior doors, pool gates, or interior doors used for safety monitoring, not for full smart-home automation. The main caveat is that placement and magnet alignment matter, especially on frames that are not flush.
Pros and cons
Pros
- Very loud alerts (rated up to 80 dB), which buyers call out as a major reason to choose them.
- Remote control lets you arm and disarm without returning to each sensor location.
- Quick setup with peel-and-stick mounting (and screws included for more secure install options).
- Door chime mode adds flexibility for entry and exit notifications.
Cons
- Magnet alignment is important; some door frames may make perfect positioning difficult, but the alarms still work when mounted more directly.
- Not a smart-home device; it is not marketed as smart-home compatible.
- Remote pairing can be fiddly for some setups (buyers sometimes need to label or pair units carefully).
What buyers think
Buyer-review evidence is fairly consistent around three themes: the alarms are notably loud, setup is fast and straightforward, and the alarms trigger reliably when the magnet and sensor are positioned correctly. Many shoppers liked that the units do not take up much space and can be installed with adhesive, while a smaller number of comments point to placement challenges on less flush door frames. There is also some limited, mixed evidence around remote pairing, where careful configuration (and sometimes separate labeling) helps keep multiple units working as expected.
What these alarms are for (and who they fit)
This is a contact-sensor door alarm system, meaning it triggers when a door, window, or gate opens far enough to separate the magnet from the sensor. That makes it a practical choice when you want immediate awareness of unsupervised access, unauthorized exits, or entry attempts, without installing a complex security system.
Best fit for:
- Parents and caregivers who want an alert if an exterior door, pool gate, or high-risk interior door is opened.
- Households that want a simple, audible notification rather than phone app alerts.
- Anyone who values a remote for arming and disarming when you are moving in and out of the home.
Less ideal for:
- Buyers who require smart-home integrations or app control.
- Homes where you cannot mount the magnet and sensor properly due to unusual framing tolerances, unless you are willing to adjust placement.
- People looking for a long-term, monitored security platform (this is geared toward local alerts, not professional monitoring).
Loudness, chime options, and what to expect
The alarm is designed to be noticeable, with a listed audible noise level of 80 dB. Many buyers specifically praise the volume and describe it as doing exactly what it is supposed to do: getting your attention immediately when the contact breaks.
It also supports a door chime approach so you can use the same system for gentler notifications in “chime” mode. The system includes four volume settings (listed as 80 to 110 dB) and four door chime options, which gives you flexibility depending on whether you want a louder deterrent-style alert or a more home-friendly tone.
Installation and placement: the make-or-break factor
Installation is meant to be straightforward. You can use peel-and-stick mounting, and screws are included if you prefer a more permanent hold. The sensor is meant for door mount use, and it is contact-based via a magnetic trigger.
Where buyers tend to succeed quickly is when the magnet and sensor are aligned with the actual door and frame surfaces. Some reviews mention that certain frames can limit perfect alignment, such as when there is a lip or spacing that prevents the magnet from sitting flush. In those situations, adjusting the mounting position on the door frame (rather than relying on a less workable spot) can help the alarm trigger properly.
Remote control, pairing, and multi-door setups
Each set includes a remote for arming and disarming. There is also support for keeping multiple remote sensors synchronized, which is useful if you are covering several doors or want multiple family members to control the system.
That said, buyer feedback indicates remote pairing may require attention. Some shoppers report that getting a single remote to operate multiple alarms can take a bit of troubleshooting, and one approach that worked was to pair and label units carefully so each door alarm behaves as intended.
Battery power and real-world maintenance
The system is battery powered. It uses a 12V alkaline battery (listed as 1 battery required for each alarm unit). Because these are local alerts rather than continuously transmitting smart devices, you can generally expect maintenance to be limited to periodic battery replacement, with some buyers reporting annual battery changes after extended use. The key is to treat batteries like any other life-safety or alerting gear: replace them when performance starts to fade.
Pros and cons recap
Go for it if you want loud, immediate notifications for door openings, you value remote arming, and you are comfortable taking a little time to mount the magnet and sensor correctly. Skip or rethink if you need app control, smart-home compatibility, or a more advanced, monitored security solution.
If you want, you can check current pricing here: Buy on Amazon.
FAQ
Is this a smart home alarm system?
No. It is not presented as a smart-home compatible device, so it is designed for local audible alerts rather than app-based control.
What triggers the alarm?
It uses a magnetic contact sensor. The alarm sounds when the door or gate opens enough to separate the magnet from the sensor.
Can you use it as a door chime?
Yes. It has a door chime mode, with multiple chime tone options.
How loud is it?
The alarm’s audible noise is listed at 80 dB, and it includes adjustable volume settings (listed as 80 to 110 dB).
Does placement affect whether it works?
Placement matters. For reliable triggering, the magnet and sensor need to be aligned on the actual door and frame surfaces, especially if your door frame is not flush.
Can multiple remotes and alarms work together?
The system supports synchronizing more than one remote sensor with the alarms, which can be helpful for covering multiple doors or giving multiple family members control. Pairing may require careful setup.
What kind of battery does it use?
It is battery powered and uses a 12V alkaline battery (with 1 battery required for the alarm unit).
Specifications
| Product Title | HENDUN Door Alarms When Opened with Remote, Door Bells Chimes, Door Security Sensor Pool Alarm for Kids Safety (2 Pack) |
|---|---|
| Category | Electronics > Security & Surveillance > Home Security Systems |
| Brand | HENDUN |
| Manufacturer | Changzhou Hengdun Electronic Technology Co Ltd |
| Model Number | SF03RCD |
| Color | white |
| Size | 2 Count (Pack of 1) |
| Item Weight | 0.1 Pounds |
| Product Dimensions | 1.57"L x 0.59"W x 3.35"H |
| Power Source | Battery Powered |
| Compatible Devices | Home Security System |
| Battery Description | Alkaline |
| Number of Batteries | 1 12V batteries required. |
| Voltage | 12 Volts |
| Control Method | Remote |
| Audible Noise | 80 Decibels |
| Mounting Type | Door Mount |
| Sensor Technology | Contact Sensor |
| Smart Home Compatibility | Not Smart Home Compatible |
| Item Dimensions L x W x H | 1.57"L x 0.59"W x 3.35"H |
| UPC | 664248657237 |
| Mfr Part Number | SZSF03R |
| Unit Count | 2 Count |
| Built-In Media | remote |
Available variants
Style
- 2pack 2x AAA batteries required (not included）
- 2pack all batteries included
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