This is a metal plate to be placed under a GPS antenna, such as for a car navigation system, when installing it on the dashboard. It is said to improve the sensitivity. The size is 4.5cm x 4.5cm, but I have kept it unused because I needed a larger size. Since it is unused, there are no noticeable scratches, but I haven't stored it with special care, so those who are concerned may find minor scratches. Please be aware of this. Shipping will generally be on weekends, but I will try my best to ship as soon as possible. It will be shipped using Mini Letter. Instant purchase is OK.