square bars, Thule Aero crossbars, most factory bars, round bars
Strap your Round Trip onto your rack.
The Thule Round Trip Case Rack Mounting Kit allows you to attach your Thule Round Trip Bike Travel Case to your vehicle’s roof rack system. Line the Round Trip Case with the protective weather stripping and then strap it to your roof using the two heavy duty nylon straps.
The kit includes two heavy-duty nylon straps with buckles, protective buckle bumpers, and weather stripping
You can make your own version for less
Familiarity: I've used it several times
It would have been nice if Thule had included this in the $430 box it's for but since they don't.....It does what its supposed to do though I'm sure you don't need the actual Thule version. Buy yourself some weather stripping and tie downs and you could save a few bucks. Though this kit will make for less work.