Disclosed are cyclic imino oligomers and polymers comprised of subunits of the formula: . An exemplary method comprises: defining at least one information, wherein the at least one information is associated with at least one security level; selecting a listening device within a listening range of the network, wherein the listening device is selected based on the at least one security level; and transmitting the at least one information to the listening device. The perforations are typically graduated from the seal edge in order to provide the best pressurisation and air-riding effect for proximity or gap control between the sealing edge and the rotating component surface.