Hang tag string loops lock fasteners, custom hang tag string for your hang tag, head lock fasteners loop hook, square lock fasteners loop hook.
I guess you bought your clothes and you don’t know how to get the hang tag and hang tag string from the collar. This depends on whether the garment supplier is a one-time or multiple-use hang tag string loops. If you use a multiple-use hang tag string loops, you can pull it off with a little force, if it is a disposable which can only be cut off.
Many brands do a one-time use of hang tag string loops in order to prevent the tag from being removed and inserted back. If it is a one-time hang tag string loops, if you dial it out hard, the loops will break, and if you plug it in again, it will be stuck. It will be broken.
There is also a loops that can be used repeatedly. The reusable dial-out loops will not break, and it will be slightly looser if inserted again, but it will not affect the use.