Halo is an 18m-diameter steel lattice structure supported on a tripod five metres above the ground.
The core is open at the top, framing views of the sky. The steelwork has a natural silver appearance, which will temper to matt as the galvanised finish weathers. A unique feature of this Panopticon is that it is lit after dark and glows a sky-blue colour, giving the effect of hovering above the town. The lighting, using low-energy LEDs and powered by an adjacent wind turbine, is designed to minimise light pollution and avoid any disruption to wildlife.