Presumably a Ninja Warrior 25SPA12.
When I took over Riff Raff from Rob it was on the CLH trailer, and I quickly transferred it to my new trailer.
It makes launching/recovering the boat very easy, especially if you have the wireless remote controls, allowing you to move freely around the boat keeping an eye on things.
I find it very useful, whether it's worth the investment would be up to you, but to me it certainly is.