An object of the invention is to convey a transfer material properly and securely in a simple structure even where space allowance is limited. The flow cell body has a lens provided on a surface thereof so as to traverse an optical path of the laser beam. This device is applied, in particular, for adjusting the features of an oscillator circuit. The selected pair of sequences is uniquely identified with the particular cell group, and the first ordering of the sequences is used only for transmission in the known one of the time slots, and the second ordering of the sequences is used only for transmission in said another known one of the time slots. Such a packet marking scheme may be used in a differentiate services communication system for proportionally distributing excess bandwidth between multiple traffic streams. The invention deals also with a silicone coating obtained by this process and an integrated circuit comprising such a silicone coating as an electrical insulator.