They're made of glossy steel buffed to an almost mirror-like finish, and there are no seams or metal burrs anywhere. Of course, they have no taste or scent, which will be appreciated by those who like to apply tongue play to their partner's trapped nipples.
They have a rather unusual design, consisting of a 1" wide ring with a hole bored in either side, through which slides a pair of thick metal posts. On the outer end of each of these posts is a flared setting that holds a clear acrylic "gem", and gives you something to grip when you're putting the clamps on or taking them off. On each inside end there is a small magnetic cross bar set in a "T" formation, which is what pinches the nipple. The overall design is good, as no matter how you move the clamps there is no chance of either of the bars coming out of the ring.
The space between the magnets opens to a maximum of 1/2", so if you have overly thick nipples these won't work. Similarly, the depth of the clamps is 3/8", which makes them difficult to place on nipples that don't stick out very far. Not impossible, but difficult.
The clamps are in no way adjustable once in place, but rely purely on the strength of the magnets to exert their force. These magnets are strong, but how tightly they fit is going to depend on the thickness and density of what they're being placed on. Attached to a pinky finger, for example, they barely grip at all. But clamped onto a very small nipple, they really pinch hard.
To use the clamps you simply pull each of the bars to separate the magnets, press the ring against the end of the breast, then release the bars slowly to trap the nipple between them. This is easier to accomplish on erect or semi-erect nipples. The bars move smoothly without a lot of unnecessary wiggle, and feel spring-loaded at first. So be warned that if the nipple is small and you let go quickly, the snap can be rather painful.
While there's nothing overly complicated about using these clamps, the ring does tend to spin on the bars, so it can be very difficult to get them in place at times. It's not something that could ever be accomplished one-handed.
Once on, the clamps feel surprisingly lightweight for their size and stay in place well with moderate movement. They could even be worn under clothing, but if you bump them too hard they will slip and possibly come off. This can be pretty painful, as they pinch harder the further they slip.
You can wash these clamps with plain soap and water, but you should avoid abrasive cleaners. You can also rub them down with isopropyl alcohol if need be, and they won't be harmed by lubes, oils, or other sex toy materials.
The Magnetic Nipple Clamps are packaged in a small metal box that resembles a tool box, complete with a latch on the front. There is a sticker on the top that identifies the contents as being nipple clamps, but this can be removed to reveal nothing but a Metal Works logo underneath. Inside is a black foam nest with cut-outs for each clamp to rest in, BUT this foam appears to contain latex, so people with allergies will want to discard it. It does lift out easily, and leaves you with a fabric-lined area that is spacious enough to store additional pairs of clamps, cock rings, bullet vibrators, or whatever other small items you might like.
A little pain is ok, but a short description of my experience with these is: Fucking Ow! No, I'm officially stating that I'm not up for extreme nipple pinching. Ah, did I say pinch? I meant bite, because I'm convinced these buggers have invisible teeth. Add that to how difficult it was to get these on my undersized man nips in the first place, and I'm not for them.
I thought he was just being a baby about these, but after a minute or two of wearing them myself I was ready to take them off too. It started out feeling like there was just some pressure, but that feeling increased the longer I wore them, to the point of real pain. I suppose that would be a plus for the some people, but it's not something that thrilled either of us.
One small warning too: the magnets are strong enough that they stick to themselves and to almost anything metal that you store them by. Keep that in mind before you toss them near something that shouldn't come in contact with magnets (like credit cards and cell phones).