RFID is known as a microchip with an antenna which ranges between one and four inches in diameter. These chips do not require any kind of power source. RFID reader is there to create the frequency and power these chips. This can be between 2 inches and certain feet depending on the signal which is set.
These frequencies are like the mobile phones. Now it is possible to track you wherever you go. These tags can be used to track the tires of your vehicle as you drive on. You may search for the RFID chip timing Irving Texas on the Internet for obtaining more information on this.