This is a magnetic reed switch (normally closed). This switch is used to detect things such as doors or windows opening and closing. These are perfect for sensing something opening and closing where there can be no mechanical interference.

Normally closed means the 2 wires coming off the switch are connected together at all times, until the magnet gets close at which point the contacts (2 wires) breaks.

Features:

• Normally Closed
• 12 Volt
• White Colour
• Water / Weatherproof
• Super small in size