US Patent 7270353 Multiple transponder seal device

The invention relates to a seal device, including a locking pin and a sleeve, the locking pin having a head and a stem having a groove which interacts with a locking ring disposed in the sleeve to lock the sleeve onto the pin by insertion. The sleeve also includes a first transponder housed in the upper portion of the sleeve at a depth that is greater than the height of the stem and the locking pin also comprises a second transponder disposed on the outer periphery of the stem. Each transponder includes storage means for storing at least one unique identification code. Thus, any unauthorized handling of the seal device may be detected even if the latter is completely replaced after breakage.