Used for measuring temperature in F or C. Each has a ~10' wire with a sensor on the end so you can put the sensor somewhere (an attic, a crawl space, or wherever) and see the temperature in that remote place displayed on the screen, which you can attach to a wall or have on a stand up to 10' away. Needs an AAA battery to work (not included).

If interested, please say in your first message when you could pick up.