In a protocol for preserving the privacy of communications between a RFID reader and a RFID tag, two distinct actions are taken. The barcode label retention device includes s at least one pair of label roll retainers, at least one pair of resilient elements, and at least one pair of fixing plates. The disc member includes an exterior wall which has a slit defined therein. A chamber is provided between the needle and syringe, in which the extraction material is arranged.