The piece of iron next to the seagull key is an electronic chip, often referred to as an RFID tag. The chip can communicate via radio waves with a reader, which sends a signal to the chip, which receives and returns the information it stores. The chip on the iron sheet is usually used for item tracking, inventory management, access control and other fields. For example, some companies use these chips to keep track of their inventory of items, and when they need some items, they can read these chips to see how much and where the inventory is. In addition, RFID technology is also widely used in public transportation, parking lots, libraries and other places of access control systems.
The iron piece next to the seagull key may be an ornament on a key chain, or it may be a tag or tag that identifies the key's purpose or owner.