Here are all the facts, experiences, techniques and media/links we have on:

Clover Nipple Clamps

also known as Butterfly Nipple Clamp

With contributions by bee. - Thanks!

Clover Nipple Clamps increase tension if pulled on. These flat clamps use spring tension to hold the clamp in place.  They are a more intense form of nipple clamp and truly something for more experienced players.  

Milovana Users

Bee: I absolutely love these!  They are severe, and you have to work your way up to wearing them for more than a few minutes.  Mine have tiny bumps that fit into tiny holes on the inside of each clamp making their grip on each nipple hurt (feel GREAT).    There is NO way they can come off by pulling on them like other nipple clamps!