There is quite a variety of nipple clamps out these days so it can be hard to know what is actually a good pick; thus I wanted to show off this pair as being the most practical I've come across.
Like probably most BDSM folks, I've ended up with more nipple clamps than necessary. Examples like the interesting looking Clover Clamp style are a classic, however pack a lot of pinch force so are a good way to make beginner submissives think nipple clamps are evil in general. Then on the other end are the danty tweezer style ones which are adjustable, but a bit of a hassle to move the slider around to put on at all or adjust pressure.
I like this particular pair for starters since the main spring has a good tension while not being over the top. The adjustment function then works as a limiter as opposed to a hard stop like some vise style clamps. Any clamps without some sort of spring tension usually require a lot of pinch force just to stay on. Using a simple screw knob, the maximum closing distance is adjusted with quite fine detail which can open way beyond a nipple in size to all the way shut / no limiter. As a usability note the knob is much easier to turn with some of the tension off so helps to squeeze the back grips a little to do so. Despite all the pluses, this is perhaps a place for improvement.
For comfort there is a nice rubber coating on the back grips and the the main pinchers. The curves of the metal seem to retain these parts well which can be a problem on other versions. It is totally no fun to keep track of if they want to fall off and if you loose them they are no longer useful with bare metal typically being a bit much on the pain scale. I also like how the chain is on a beefy ring in the back middle of the clamp as oppose to connected to one of the grip ends. This way the chain connection is more independent from the clamps and hangs down nicely.
Although likely not looking like a super impressive item, I felt worth sharing since they are the best I've had for usability and can be adjusted for a great range of tit play intensities.
I purchased mine in the MR-S Leather retail store, but appears they are not currently shown online at this time.
