A polished glass disk medium substrate suitable for use as a substrate for a hard disk, a hard disk containing the substrate and methods for making the substrate. The nozzle has at least two cylindrical chambers, placed inside an outer cylindrical body and fluidly separated, for the respective passage of the first and of the second viscous material, each of the at least two chambers having an outflow section of the relative viscous material substantially positioned in correspondence to a delivery mouth. Additional impactshock absorption is provided by exterior features of the apparatus, including a peripheral bumper having a plurality of raised spring-like protrusions, and rubberized and contoured features of the device housing. These elements do not hamper the winding, unwinding, or retraction of the wire. Thus, the entering peer is enabled to download, with the expected probability, the requested data content from a selected one of the randomly selected peers having a lower latency than that determined for the entering peer.