These beautification rings are an awesome addition to your piece. They give your piece a more complete look by screwing over the threads in between the mod/battery and the tank. If your atomizer is slightly fatter than your mod or battery these will give it a sleek and more complete look. These rings also add more stable feel for to your piece by giving your atomizer a place to rest on. They also take the stress off the threads of the atomizer.
These will screw onto most 510/eGo style batteries and also most mods.