This is Sparkfun part DEV-13343.
The LilyPad Reed Switch is a simple breakout for a reed switch that will make it easy to use in e-textiles circuits in exactly the same manner that you can currently use the LilyPad Button and Switch. In order to make it more durable for wearable use, we’ve used a different style of reed switch, which is insulated. This means that the same glass switch is encased in black plastic, making it much more difficult to break, but it works in exactly the same manner.
A reed switch is a simple mechanical switch that is activated via a magnet. When the device is exposed to a magnetic field, the two ferrous materials (reeds) inside the switch pull together, and the switch closes. When the magnetic field is removed, the reeds separate and the switch opens. This makes for a great non-contact switch that can carry up to 1A and 0.25A while switched.
This is a brand-new, old-stock item that has been in storage. Full warranty and technical support. Click here to learn more.