In my time, I have tried many types of nipple clamps as an addition to various forms of play. But my favorite style of clamps to use have always been the Japanese Clover Clamps.
And now I have a black pair!
The Uberkinky Monarch Noir Nipple clamps are almost identical to the standard Japanese clover clamps, but the fact that they are a very suave and gothic looking black with a lovely little black chain attaching the pair together makes them far more pretty to use. Which is a big bonus in my book.
The tips of the clamps are rubber coated with 5 little nodules to assure a decent grip and unlike some clamps that I have seen on the market, these are not adjustable. They essentially bite down as hard as they can from the first moment you use them and the more you flick them or move them around, the more settled and tighter the clamps become.
One thing that I feel a need to point out is that part of the pain and sensitivity that any nipple clamps cause comes from the restriction of the blood flow to the nipples. When they are removed the pain can end up being worse than when they were applied as the blood flows back into the nerves around the previously clamped area and they begin to rage at being squished and deprived of body fluid for so long. It is never a good thing to leave them on for too long.
As an added bonus, If you want some reliable hints and tips on how to use nipple clamps effectively, Uberkinky supply a helpful little guide: http://www.uberkinky.co.uk/essential-guides/nipple-clamps-guides/how-to-use-nipple-clamps.html
When used correctly, nipple clamps can be an exciting and attractive addition to many forms of BDSM play. I highly recommend that everyone has a pair added to their arsenal of toys.