I was ecstatically impatient to try these out, and they sat around in my toy box for over a week due to life getting in the way. However I managed to break these babies in and boy am I mad that I didn't play with them sooner.

From the thin packaging they may look as if they are newbie clamps. You know the ones that "look" like they don't hurt and actually live up to the assumption. These are not the case. The Japanese clover clamps went far beyond my expectation of nipple clamps, especially for the price.

They are light weight, yet sturdy. A bit big in size in comparison to the actual part that goes on the nipple itself. The clamps are stainless steel with white rubber tips on the clamp base. This white rubber tip is hard and riveted, resembling tiny shark teeth. They also offer versatility, with their attached white strings that could easily link to a small chain and/or weights for added pain/pleasure.

Goes well with: Pair with other sensation toys or combine ice cubes or a gel the warms when you blow on it to add to the sting. I'm almost certain that sadists alike would find a number of things to incorporate with these clamps to intensify the pain.

Care: After playing with these clamps I suggest a damp cloth with a mild sanitizer or soap to give them a quick wipe down. Let them air dry completely before stowing away.

Storage: I suggest keeping them in a zip-lock baggie or small pouch to prevent them from getting tangled in your toy box and from getting lost.

Travel: These are easy travel companions for a road trip. Easily fitting into your purse. I'm not certain if they are air travel friendly and wouldn't risk them being taken by a freaky TSA.

Tugging, Pinching, Pulling, Constant Clamping- I did all that and more to my partner's nipples with these babies! When we were done his response was "These are definitely not for newbies!"
I hope that answers your question as to their effectiveness.

If you are a newbie to nipple torture, you don't have to squeeze hard down on these clamps to get a feel for them. It's not the clamps that aren't for newbie simply the technique and usage of them.

Of course pay attention to your partner's reaction during this play as it's easy to get caught up in the moment. Just like with any other instrument you use, play responsibly.