An object is disclosed, the object (100) comprising a body comprising an antenna; and an integrated circuit embedded in the body and electrically connected to the antenna for receiving and transmitting wireless signals. The integrated circuit receives wireless signals at first and second different frequencies, waits until a command is received at the first frequency from a first reader device before transmitting a first signal and, upon detection of a signal at a second frequency different to the first frequency from a second reader device (201), transmits a second signal without waiting until a command is received.