These came off of a house built in 2003, only one coat of paint on them.
6 1/4" at top, 7 1/2" at bottom, includes foam caps and bases. Columns are 8' tall, decorative caps and bases slide over outsides.
Vinyl rails were attached to them so they have small screw holes that can easily be filled.
They appear to be "Endurastone" (Fiberglass Reinforced Polymer), heavier than regular fiberglass.
$50 each, sold only in sets of two.