OK, several questions and one comment:
Questions: That picture actually raises more questions than it answers, like how does that hook onto the topper? Does it lift the topper from something attached to the top? If it hooks to the bottom edge of the topper how do you keep the weight of the topper from causing the topper sides to flex outwards? If there is some kind of bar underneath the topper how do you lift the topper up high enough to slide the bar through? And then once the topper is up, do you leave it hanging or lower it to the ground?