> For the complete documentation index, see [llms.txt](https://learn.arduinosa.co.za/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://learn.arduinosa.co.za/sensor-kits/37-in-1-sensor-kit/mini-reed.md).

# Mini Reed

![](https://451694785-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MPda5vaSVRKTQ6AoAmb%2Fuploads%2Fgit-blob-f103020e2e0ae3250ad7260979e2d48e6f2f0ef5%2Fimage.png?alt=media)

The reed switch is connected between the two outer pins on the PCB. Without a magnetic field the contacts remain open. A built-in 10 K ohm resistor is connected between the centre pin and the ‘S’ pin. It can be used as a pull up or pull down resistor.