Yeppers, like K-9 said. You simply hook it on the rack and run the strap out to an anchor point. I'd mount it sideways on my rack to store it. Hook it on one side, hook the strap on the other side and crank it down tight. I "THINK" you can also turn the mount around if you don't want to use the curved part to hook on the rack and possibly use a bolt to hook it on your trailer ball mount. (you can see the bolt hole in pic #2 & #5) I never did that as I had a trailer ball on mine. To answer your question, it "sits" on the rack ... if you bolt it on you lose the versatility (portability) of moving it around (front to rear, etc.)