Love that pic in your white thong!This thread certainly has some impressive heads!
We don't have this type of door knobs in Sweden.
But it seems that your door knobs are around 2 inches in diameter?
So I had to compare to a butt plug 1.93 inch in diameter.
http://www.lpsg.com/members/northernlights/albums/head/883435-head-comparison-to-plug-1.jpg
http://www.lpsg.com/members/northernlights/albums/head/883436-head-comparison-to-plug-1.jpg