That looks like the handle of a mixing spoon or other such utensil. I sometimes use one instead of my sounds as it's a little larger than any rods I have. I'm guessing it's around 11mm or so because it's a super snug fit and won't just slide in. Looks like you've got a big ol' P.A. HOT!
Your very observant my friend. Yes it is a plastic spoon from Target that when I saw it I got a woody just thinking of the posabitlites ;-). Just moved up to a 2 gage ring and the extra weight feels awsome on the end of my dick!!! Hope to have some more sounding vids in the future. Keep checking back.