We have the 32 U.S. gallon model like in the video that gashog posted, except ours has pneumatic tires so it's much better to tow for a distance. With a bad back, I need a model I can tow rather than having to lift it. We only use it for the grey tank. I had to toss the bobber gauge because it wouldn't allow air to escape the tank so the grey water could fill it. I'd like to figure out a way to secure the hoop that goes over the hitch ball. When going down a hill with a full tank it makes me a bit nervous. Other than that it works well and I'm happy with it. I have enough room in the pickup bed to carry it there.
2011 Rockwood Signature Ultra Lite 8293SS, 12K Equal-i-zer
2016 Ford F-250 XLT SuperCrew, 6.2L, 4x4, 6'9" bed, 3.73
2010 Rockwood Roo 23SS (2012 - 2014)
2009 Ford F-150 XLT SuperCrew, 5.4L, 4x4, 5'6" bed (2012 - 2016)