KZ offers the sidewinder as an option, however mine originally came without and I had the dealer install. My only issue is that the dealer didn't properly lube it while putting it together so it used to not track 100% right at times. I dissassembled and lubed per manafucturers instructions and it's much better now.
Also they installed the wedge not quite right so there was a lot of banging at the hitch, to the point the threads that the plate attaches to, which is nothing more than a nut welded inside, now spin freely. I talked to Reese at the Hershey show and they were going to give me a fix, but I have a way to get it tight now.
Overall I am very pleased with the king pin, I would not be able to get mine in the driveway without it, or a slider, but I didn't want a slider because I didn't have budget for the auto ones, and didn't want to have to deal with something else back there.
2008 Tiffin Allegro Bay 38TGB
2005 Saturn Vue
Stella and Luna, our 2 shelter rescues