The non-piercing nipple rings are made to look like you have pierced nipples. I wanted to see what my nipples would look like if they were pierced. I did like the way they looked, but damn they hurt!

These could be used as a clitoral hood clip, or on the labia. They would be very painful if used on these areas and I really wouldn't recommend these to first time users. If you know you like tight fitting nipple rings or nipple/clitoral torture then you'll love these little guys. If you aren't sure try something more adjustable.
Guys can use these on their nipples, scrotum, or penis.
They can be worn under clothes, and are easy to use. They will stay on well enough but can be pulled off, though you will notice that happening!

The ring is silver metal and on the ring is a smooth plastic bead that is a sort of clear blue in color. It is meant to look like a crystal bead. The bead had a light plastic smell, but after I washed it it went away.
The silver ring is smooth and seamless to the point of the little balls that pinch the nipples to hold the ring in place.
You pull apart the ring to slip the small metal beads on either side of the nipple. The ring is sturdy and resists being bend out of shape. I am not sure if the metal will corrode but a tiny bit of clear nail polish will help protect the metal from rusting.

The metal this ring is made of is sturdy and not flexible at all. This makes it hard to pull apart the sides of the ring. They do not stretch out easily for this reason I would caution against using these on larger sized nipples. They are mildly adjustable but won't pull out of shape easily.
At first, they are uncomfortable to wear but if you can withstand the pain they are great. The rings will work on any size nipple, but for larger nipples it can be very painful at first. They are fairly easy to place and stay on quite well.
I love the look of them, but they aren't for beginners or for anyone who can't handle pain.
The rings weigh about 1 ounce but it is the pinch that hurts not the weight. They are approximately 1/2" in diameter.

I washed mine with mild soap and water. I made sure that I dried them very well to avoid the metal rusting. You could also just wipe them with a commercial toy wipe, or some rubbing alcohol. I store mine with my other jewelry.

I tried wearing them a few times, but could only handle them for about five minutes at a time. I was upset because I really like them! I am going to keep trying until I can wear them longer; possibly to a play party sometime soon. I keep working on it, to build up my pain tolerance levels.