The product is a pack of 10 re-writable 125Khz RFID proximity ID card token tags key fobs. Made of ABS material and measuring 35 x 29 x 5 mm in diameter, these blue key fobs are branded and manufactured in the United Kingdom. They are designed for home security systems and feature a key fob design with a specific operating range and compatibility. Each key fob does not require batteries as they are re-writable and can be programmed for specific access control purposes.