I picked mine up from a vender at Dumont. I think the mount was $25.00, which is about the same price I found for a 0" drop hitch at the part store, but the hole drilled for the ball is too big compared to the flag mount hole. I then used their mounting, which they have a few different times, but they warranty all their own products. I used the lighted whip mount because I have a LED pole for night time cruising. They have a quick release that is like mine with a small pin to hold it in place. That one is preferred because it will allow the pole to rotate in the wind and not have the flag wrap around on it self.
Here is a link to their website, but its not listed on there.
clickwhip.com