# Door magnetic contact sensor BLOW 4919# HO-03B white — wired door/window sensor

**URL:** https://aio.lv/en/product--blow-4919--11863695
**Data updated:** 2026-03-09 17:40 (EET)
**Category:** Smart Sensors
**Manufacturer:** BLOW
**Manufacturer code:** 4919#
**EAN:** 5900804098904
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 5.49 €
**Prices and availability valid until:** 2026-07-18 23:59
**Price without VAT (21%):** 4.54 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--blow-4919--11863695

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 13.07.2026 | free |
| Pickup points | 16.07.2026 | 1.99 EUR |
| Courier delivery to door | 16.07.2026 | 4.99 EUR |

## Summary description

Wired door/window magnetic contact sensor BLOW 4919# (HO-03B) in white. Designed to detect opening and closing of doors or windows via a reed switch (kontaktron). Suitable for integration with alarm and security systems, providing a simple normally closed/normally open input for control panels and home security setups. Compact and mountable on frames and sashes.

## Long description

Wired door/window magnetic contact sensor BLOW 4919# HO-03B in white is a compact contact switch designed to detect the opening and closing of doors and windows. The device uses a reed switch (kontaktron) and provides a straightforward normally closed (NC) or normally open (NO) input for connection to alarm control panels, access control units, or other security systems. Its small form factor and surface-mount design allow installation on frames and sashes where reliable state detection is required.
Advantages
The BLOW 4919# HO-03B offers a simple wired interface compatible with many alarm panels and controllers, ensuring predictable behaviour in security installations. Its reed-switch mechanism delivers mechanical reliability with low power consumption and long service life. The sensor’s compact and unobtrusive white enclosure enables discreet mounting on most doors and window frames while maintaining consistent contact alignment between magnet and sensor.
Suitable for
 Perimeter security for residential doors and windows
 Commercial premises where wired inputs are preferred for integration with alarm panels
 Access control systems requiring door state monitoring
 Auxiliary monitoring of cabinets, shutters or gates with compatible mounting
Key specifications
 Type: Wired magnetic reed contact sensor
 Contact configuration: Supports normally closed (NC) and normally open (NO) wiring
 Mounting: Surface-mount on door/window frame and sash
 Housing colour: White
 Detection method: Magnetic reed switch (kontaktron)
 Application: Designed for integration with alarm and security control panels
How to use
Mount the sensor body on the door or window frame and align the magnet on the moving sash so the two parts are flush when closed. Connect the sensor wires to the alarm or control panel input according to the required normally closed or normally open configuration, following the panel manufacturer’s wiring diagram. Ensure cable routing avoids sharp bends and protects against mechanical damage; secure wiring with clips or conduit where appropriate. After installation, test opening and closing to verify reliable state changes are reported to the control system.
Usage recommendations
Install the sensor where the magnet and contact maintain consistent alignment; keep the gap within the manufacturer’s recommended distance. Use appropriate insulation and strain relief for exposed wiring and verify compatibility with the control panel’s input type and end-of-line resistor requirements if applicable.

## FAQ

### How much does the Door magnetic contact sensor BLOW 4919# HO-03B cost, and is it available for purchase?

The price is 5.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 30 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 13.07.2026 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, Bank cards on-line, Apple Pay, Google Pay. 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 BLOW 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 BLOW 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/11863695/67262355_large.webp