The Foamboard/ Polyholder has a 28 mm spigot with a ball-and-socket joint to allow rotation and flexible positioning.
The board "clamp" has two sides, one white for the reflective side of the polystyrene; one black for the light-stopping side. It doesnt damage the foam or bead board
Two metal spikes (on wire retainers) keep the polystyrene board firmly in place.
Mounts into 2k female