Another tip for this. I wear mine over my flight suit and under my vest. I have put 3 snaps in. One at the lower back and one on each side. Attach the snaps on the bottom side of the harness. Then they snap onto the flight suit. This keeps the harness from riding up as the day goes on. The first time it rode up two inches, so the jet pack lowered down my back two inches. After this adjustment, it has not moved at all. So far it has worked very well, no sore back and really don't feel the jet pack at all. Ron and I love them. And for how they work, you sure can't beat the price! But you do have to go to the evil orange empire!