A scroll compressor is disclosed. The lens receives collimated laser light from the scanning laser ophthalmoscope and, focuses on the fundus of the eye. In some embodiments, the hold limit is based at least partially on an account balance associated with the payee account, and one or more other characteristics associated with the payee account. The conducting element is hermetically sealed with respect to the base body, at least in part. Multiple diagnostic ports can be provided to allow separate determinations of leaks about the different portions of the high pressure seal. In addition, the socket is provided with a post at an inner surface end portion thereof which fits within a pipe fitting at an end of the valve to provide a firm and stable fit of the socket on the valve.