# Door sensor Ajax DoorProtect Plus Black — wireless, battery-powered, model 38100.21.BL1

**URL:** https://aio.lv/en/product--ajax-3810021bl1--10978997
**Data updated:** 2026-02-13 15:45 (EET)
**Category:** Smart Sensors
**Manufacturer:** Ajax
**Manufacturer code:** 38100.21.BL1
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 48.49 €
**Prices and availability valid until:** 2026-07-26 23:59
**Price without VAT (21%):** 40.07 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--ajax-3810021bl1--10978997

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 03.07.2026 | free |
| Pickup points | 08.07.2026 | 1.89 EUR |
| Courier delivery to door | 08.07.2026 | 4.99 EUR |

## Summary description

Ajax DoorProtect Plus Black is a wireless, battery-powered door sensor (model 38100.21.BL1) designed to detect door opening and tampering. It integrates with Ajax security systems to provide reliable intrusion alerts, supports easy installation on doors and frames, and offers long battery life for maintenance-free operation. Ideal for homes and small businesses that need discreet perimeter protection.

## Long description

Ajax DoorProtect Plus Black is a wireless, battery-powered door sensor designed to detect opening, closing and tampering on doors and frames. The sensor integrates with Ajax security systems to deliver intrusion alerts and tamper notifications via the hub. Its compact black housing and magnetic contact make it suitable for discreet installation on a variety of door types, while battery operation eliminates the need for wiring and allows flexible placement.
Advantages
The device provides reliable detection of door opening and separation using a magnetic reed switch and intelligent signal processing to reduce false alarms. Battery-powered operation with optimized energy consumption ensures long service life and low maintenance. Wireless connection to the Ajax hub enables fast alarm transmission and remote status monitoring. The slim design and black finish allow unobtrusive mounting on most door frames and doors, and built-in tamper protection alerts to unauthorized removal or manipulation.
Suitable for
Residential entry and interior doors where discreet perimeter protection is required
Small offices and retail premises for monitoring customer access and after-hours security
Server rooms, storage areas and utility closets requiring door-open alerts
Temporary installations or rented properties where wiring is not an option
Key specifications
Communication: wireless connection with Ajax security system
Power: battery operation for cable-free installation
Detection type: magnetic contact for open/close sensing and tamper detection
Placement: suitable for doors and frames with standard gap tolerances
Form factor: compact, low-profile housing in black finish
How to use
Mount the sensor body on the door frame and the magnet on the door so that the two parts align within the specified gap tolerance. Follow the Ajax system pairing procedure to register the sensor with the hub and verify signal strength before final installation. Use the Ajax mobile app or hub interface to configure notifications, alarm responses and tamper settings. Periodically check device status in the system to confirm battery level and connection quality.
Usage recommendations
Place the sensor where the magnet and sensor align reliably when the door is closed; avoid metal objects or strong magnetic fields near the contact area. Test the sensor after installation and integrate it into the Ajax system scenes or automation rules as needed. Replace batteries according to system alerts and follow local disposal regulations for batteries.

## FAQ

### How much does the Door sensor Ajax DoorProtect Plus Black 38100.21.BL1 cost, and is it available for purchase?

The price is 48.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 1 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 03.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All Ajax products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized Ajax service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

https://aio.lv/img/cache/product/10978997/61412334_large.webp