Panasonic window sensors, set of two. These function as an option for the company's telephones. One is new and unused, and the other was used for six months. Product: Window sensor (photos 2, 3, and 4) Model number: KX-FSD10 Condition: New, unused Quantity: 1 Included items: Magnet, spacer, "Monitoring in progress" sticker, lithium battery, spacer quantity confirmation sheet, extension number sticker, instruction manual Product: Window sensor (photos 5, 6, and 7) Model number: KX-FSD10 Condition: Used for about six months, no double-sided tape on the main unit Quantity: 1 Included items: Magnet (no double-sided tape), spacer, "Monitoring in progress" sticker, lithium battery, spacer quantity confirmation sheet, extension number sticker, instruction manual Purchased on Amazon in October 2021. One window sensor is new and unused, only opened. The other was used for about six months and then stored in a warehouse. The new unit has not been tested for operation as it is unopened. The other unit was confirmed to be working with the company's telephone, VE-GD-35. The used unit has some traces of double-sided tape, but is otherwise in good condition with no noticeable scratches or stains. #KX-FSD10