Thanks for all of your helpful replies
.
I got in touch with the folks at Carry Freedom in Scotland and they suggested I get their newer, improved hitch, called the Lollipop. They even gave me a discount as I own one of their older trailers.
The red piece is made of of some kind of flexible plastic, which gives if the bike falls over. The old ones were metal and could be damaged if this happened. I really like this hitch and recommend getting one if you have an older model Carry Freedom. I think the Lollipop might work on some other trailers, too.
