Disclosed herein is a pull-down fastening device for objects having bores, with a fastening unit which includes a fastening element. In the case of ball bearings, point contact is obtained. A selection unit is coupled to the elements and an adder is coupled to the selection unit to sum the outputs of the weighted elements. In this manner, a light dimming dot pattern with a transmittance for all light rays of approximately 62%, higher than the transmittance for all light rays in the conventional technique not higher than 50%, is produced. The invention may be used with almost any type of portable devices. The communications module configures the processor to generate a first transmission sequence number associated with a transport message to be sent to a remote device, include the first transmission sequence number in the transport message, and send the transport message to the remote device.