# Magnetic Reed Switch (Kontakttron) KN-04C — cylindrical sensor, normally closed, compact form

**URL:** https://aio.lv/en/product--no-name-kn-04c--11959817
**Data updated:** 2026-03-11 13:59 (EET)
**Category:** Smart Sensors
**Manufacturer:** No name
**Manufacturer code:** KN-04C
**EAN:** 5902887018350
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 3.99 €
**Prices and availability valid until:** 2026-07-17 23:59
**Price without VAT (21%):** 3.30 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--no-name-kn-04c--11959817

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 08.07.2026 | free |
| Pickup points | 13.07.2026 | 1.99 EUR |
| Courier delivery to door | 13.07.2026 | 4.99 EUR |

## Summary description

Cylindrical magnetic reed switch KONTAKTRON KN-04C is a compact sensor that detects proximity of a magnetic field. Designed as a normally closed reed contact, it serves for door and window monitoring, alarm systems, or simple position sensing. The small cylindrical form factor enables mounting in frames or housings where space is limited.

## Long description

The Magnetic Reed Switch (Kontakttron) KN-04C is a compact cylindrical sensor that responds to the presence of a magnetic field. Configured as a normally closed (NC) reed contact, it is intended for basic proximity detection and security monitoring applications such as door and window sensors or simple position sensing in confined spaces. Its small diameter and cylindrical shape allow for installation in narrow frames, housings, or recesses where larger switches would not fit.
Advantages
The KN-04C reed switch offers a low-profile cylindrical design that simplifies discreet mounting and integration into door and window frames. As a normally closed contact, it provides a defined default circuit state that can be monitored for open/closed conditions. The mechanical reed construction ensures passive operation without the need for onboard power, providing reliable switching when a compatible magnet approaches. Its compact dimensions reduce the need for structural modifications during installation.
Suitable for
 Door and window alarm contacts in residential and light-commercial systems
 Position sensing in small enclosures or housings
 Simple proximity detection in automation or DIY electronics projects
 Replacement of larger reed switches where space is limited
Key specifications
 Switch type: Normally closed (NC) magnetic reed contact
 Form factor: Cylindrical, compact body suitable for recessed mounting
 Operation: Magnet-actuated proximity switching
 Connection: Leads suitable for wiring into alarm circuits or low-voltage systems
 Typical use environment: Indoor installations, protected from direct moisture ingress
How to use
Mount the KN-04C sensor in the fixed part of the installation (frame or housing) so that a separate magnet can be positioned on the moving part (door, window, or panel) to actuate the contact when closed. Wire the sensor leads into the alarm or monitoring circuit according to the system's wiring diagram, taking account of the normally closed behavior so the controller or alarm panel can detect an open circuit. Ensure the magnet aligns with the switch when the moving part is in the closed position and verify correct operation by opening and closing the moving part while observing the system response.
Usage recommendations
For reliable operation, select a magnet with appropriate strength and ensure correct alignment and distance between magnet and switch. Protect the sensor from direct exposure to liquids and excessive mechanical stress. Use in low-voltage alarm and monitoring circuits; avoid connection to high-voltage mains circuits. Test the installed contact periodically as part of routine maintenance to confirm consistent switching behavior.

## FAQ

### How much does the Magnetic Reed Switch KN-04C cost, and is it available for purchase?

The price is 3.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 2 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 08.07.2026 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 No name 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 No name 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/11959817/67405224_large.webp