Picture hook. Very good discreet picture or mirror holder. I used mine to fix a mirror to the back of a door (for doing my hair) that I did not want to mark permanently by making a hole in it. It is excellent value and has done the job of holding the item in place. It’s best to use picture wire on the mirror/picture as I did as string is to thick for the grove.. it holds the mirror flat as the hook doesn’t protrude very much at all which is good as your picture/mirror isn’t tilted. The mirror was 4lb just 1lb under the weight the instructions said the hook would hold so not a completely light mirror and I feel quite happy with the strength and holding power of the hook. Would recommend the picture hanging hook which can be removed from your wall or door in my case and leave absolutely no marks(I haven’t removed the hook myself yet but have been told by friends it does remove easily and mark free).