I brought these on a cruise to hang an extra mesh organizer for toiletries, and to hang jackets I wouldn't need until after the cruise and were a bit bulky in the small cabinets on board. These hooks are seriously heavy duty and insanely useful. They were very easy to use. When traveling, I left them in the plastic case they came in, where they're attached to a magnetic strip with the hooks separate. I had no trouble going through TSA at multiple large airports.On board the ship I just quickly screwed a few of the hooks in and they attached to almost every surface I tested them on. I used hooks on the ceiling for jackets/coats, and hooks in the bathroom for my mesh organizer. Not only did nothing I hung slip or move at all during the week long cruise, it actually took a little effort to pull the hooks free at the end. The ceiling hooks were easy, but the hooks on wall surfaces were actually easier to slide along the wall until I reached a bend where they could be slid off haha. They do pull off normally too with some strength but I was very surprised how well these things hold in place. I really didn't need the 80 lbs version... 30-40 lbs would have done just as well.On Royal Caribbean ships, these attach to all of the doors, normal walls, and ceilings in staterooms and connecting bathroom. The only things they didn't attach to were furniture, and a few of the fancy lighting strips and decorative/textured wall bits on Icon of the Seas, but it's pretty obvious that they wouldn't, I just wanted to test everything.