I was a little dubious about this nipple suction item, and was happy to be proved wrong!! I've tried some others that weren't super great. I love that they're transparent so you can see yours or a partner's nipples swell! Also, depending on how much you pinch the little bulb, you can adjust the pressure: slight pinch, less tweak; pinch completely so the sides are touching, VERY STRONG TWEAK! Highly recommend
on a less fleshy area on my body while in the store. I was being silly and tried them on my forehead (I was trying to look like Shrek), and after leaving them on to laugh for 30 seconds, it left circular marks for a few days! That totally proved how powerful these are, and I bought them soon after. They're stiff enough to get a firm grasp and hold their shape during play, but pliable enough to squeeze to get air out in order to properly suction. These are a staple.
Even the smallest pinch of the bulb can result in some intense pressure. These feel great on the nipples, clit, anywhere on the body where there’s a little meat. The bulbs are a little cloudy, but you can still see your/a partner’s bits as they swell fairly clearly. Depending on how much you’ve squeezed, the bulbs do tend to fall off after a little while, but these are perfect if you’re interested in starting suction-y nipple play. Great for solo kinky play. Use with caution!
I really like the Tweak. I use toys like this to bring blood into nipples or a clit. It's made of a thick, stiff elastomer that can give a smidge more psi than some of the glass sets, (which tend to have a thinner, soft rubber bulb, which doesn't expand with the same force.) As an added bonus, I don't need to worry about the material shattering like glass might, so I don't need to worry about chucking it in a toy bag, or dropping/accidentally stepping on it at a dark play party.