Are these suction cups or adhesive hooks?

They are true suction cups. The sticky feeling is from a special gel that aids installation and creates a superior seal, not a permanent glue. The twist-lock mechanism creates the powerful vacuum hold.

How can I make sure it sticks securely?

1. Ensure unscrew the knob counterclockwise to remove the handle and covers, do not simply attach the whole hook directly at first.

2. Firmly attach the hook base, press to release air, reassemble covers and knob, press again, then tighten clockwise.

Will these work on a fully tiled wall and hold up in steam?

Yes. They are proven to work on all-tile walls and shower doors. The strong vacuum seal holds firmly even in humid bathrooms, with no slipping.

Do they leave marks? Can I remove and reuse them?

No marks, and yes, they are reusable. Multiple users love that they can be removed and repositioned all over the house without damaging walls or doors.

What can I hang with these?

Very versatile! Customers use them for heavy towels, robes, holiday wreaths, and decorations. One user confirmed it holds a 10-pound wreath decor on their front door perfectly.