A method and device is provided for dynamically maintaining and updating public key infrastructure certificate path data across remote trusted domains to enable relying parties to efficiently authenticate other nodes in an autonomous ad-hoc network. The arms terminate distally in fingers which are of reduced width and thickness relative to the arms and which are adapted to be bent towards and past each other. The flexible sizer body includes an outer ring and an annular wall coupled to and extending from the outer ring. The loudspeaker plays a segment of sound to be received by the array microphone. The second frame is assembled with the first frame for fixing the liquid crystal display device panel.