These are safe to use,and have imperfections in the finish.
Can have -
Tiny gaps in the colour,usually on the inside which will be more than what would be acceptable for 1st grade.
Larger than acceptable bracket marks
May be slightly blotchy under close inspection.
The rings will usually (99% of the time) only have ONE of these defects.
They have all still gone through the same safety tests and passed.
They will almost certainly not be noticeable when sewn into a sling.
Colours chosen at random.