# Magnetic contact switch (door sensor)

**Type:** Product page · **SKU:** ADA375 · **Brand:** [Adafruit](https://core-electronics.com.au/brands/adafruit-australia)
**Page:** https://core-electronics.com.au/magnetic-contact-switch-door-sensor.html ([markdown](https://core-electronics.com.au/magnetic-contact-switch-door-sensor.html.md))

## Retired product

This product is retired and no longer available for purchase. Replaced by: CE09248.

**Replacement:** https://core-electronics.com.au/catalog/product/view/sku/CE09248

## Description

This sensor is essentially a reed switch, encased in an ABS plastic shell. Normally the reed is 'open' (no connection between the two wires). The other half is a magnet. When the magnet is less than 13mm (0.5") away, the reed switch closes. They're often used to detect when a door or drawer is open, which is why they have mounting tabs and screws. You can also pick up some double-sided foam tape from a hardware store to mount these, that works well without needing screws.

### Technical Details

- Normally open reed switch
- ABS enclosure
- Rated current: 100 mA max
- Rated voltage: 200 VDC max
- Distance: 15mm max
 
Dimensions:

- Box size (each side): 29mm x 14mm x 9mm / 1.1" x 0.6" x 0.4"
- Cable Length: 305mm ± 12mm / 12" ± 0.5"
- Weight (per side): 5.4g
 
Netduino driver and Netduino sample. This sample shows how to use an interrupt handler to respond to a button press or a magnetic contact switch closing.

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/3/7/375-00.jpg)