A bollard comprises an elongate outer tubular cover, an elongate inner tubular core located within the outer tubular cover, a damper located at a lower end of the inner tubular core, and a washer arranged to locate the damper against the inner tubular core. The design methods construct a plurality of configurations, which including waveguides, via holes, metallic posts, and conductor planes in the structures, for selecting, coupling, converting, and dissipating of the signals with specific electromagnetic modes and frequencies propagating through the structures. The handle may be adapted with a plurality of ventilation holes to enable air to pass through the handle.