Ceiling light parts

for ceiling lights of the 2 metal rails with clip-on-lights type (rails as open metal parts that are at ~12vac usually)
circular part to go on the ceiling, spacer to be put between the rails.
the circular part is initially been meant as an adapter from mounts with central screwhole for fixture to circular mounts with off-center holes.
one can also press-in a hexnut in the circular piece.
the spacer is designed to take a hexnut and be used with the hexnut facing downwards (towards floor). small square cover for covering the hexnut

mount square cover with 2mm selftapers, for best effect / least visability of this being a DIY Hack-thing use filament color to match the color of the selftappers