The listing is for one ring with deep green Uvite Tourmaline. It will make a perfect gift for someone born in October, as Tourmaline is one if October birthstones.

The stones are rather small, but not tiny, 3 to 6 mm. The rings come in US sizes 6, 7 and 7 1/2, and also can be resized to plus 1/2 size up. You can see the sizes on one of the pictures. If you are not sure about your size, this might be helpful: findmyringsize.com.
The ring band is 1 mm thick and is sturdy although it looks very dainty on the finger.