The reviews on it will probably be filled with that info.

it does not hurt

I tried mine out for the first time today and there was no pain at all. I have larger nipples so it took some time to figure out how to place them properly, but there was no pain during that time either. I was expecting it to really exert some hard pressure/pain based on the reviews, but it gave me a pleasant pressure-like feeling. They look amazing on! It was a complete turn on for my partner. I will agree with the reviews that the crystals are not super bright and sparkly, and the clamps are lighter than one would expect. Definitely watch the video on how to use them. It was very helpful!

They dont hurt me I wish they were stronger.

I just got mine yesterday. I am not a fan of nipple clamps, because my nipples are very sensitive. Well tried them on this morning and they were fine. They were tight on my nipples yet not discomfort from the squeezing. I will admit my nipples are rather large and barely fit that too might have helped. I love them.

Not very painful according to reviews

Hmm... I'm definitely interested in trying these as well! Most nipple clamps are either too severe (clover clamps) or fall right off (tweezer clamps). If these will work for larger nipples that would be perfect!

Thanks for posing this question and thanks for everyone's feedback. I have large nipples as well and have a hard time finding something to work right, I am going to check these out.

Not that painful, but I suppose you can stress it, but it would give back out

I've been interested in these as well