When I was looking at what to get I found this website that sells them:
http://www.ponddampiping.com/accessories1.html It's the second item on the page. I ended up just using a 10" PVC pipe over my 6" metal pipe. The pic below just looks like a PVC pipe sticking up out of the ground. But there's actually a metal pipe inside of it. I cut some holes near the bottom of the PVC pipe to let the water in.
The drain pipe has been leaning for as long as I remember. My grandma says it started leaning soon after it was put in. But it hasn't moved since then (20something years) so I'm planning to leave it leaning for now.
