A reusable holder for contact lens cases includes a base, at least one receptacle formed in the base configured to receive a contact lens case, and a time keeping device formed in the base. The system can generate a new data stream that includes an identifier to any data block that has been broadcasted recently, and includes an encrypted block-decryption key that allows the recipient of the data stream to decrypt the data block. The keypad may be mounted on a slider for sliding into and out of a main body of the terminal. 02 at most, and the O2-concentration being kept between 0. The pressure difference detection mechanism 15a detects the pressure difference between the upstream side and the downstream side of the throttle portion 15b in the refrigerant flow thereby to detect the flow rate of the refrigerant discharged from the compression unit 11. Another embodiment includes metal coils for generating an electric charge for charging a battery upon movement of the traveler through the coils.