All measurements are approximate:
These are thin-walled silicone eyelets that make your piercing look like a round, open hole. They should not be used to stretch with, as they may be unable to keep a freshly stretched piercing at the new size. The flares on these are not like regular plugs where they come out and around your lobe--they are extremely small flares that barely come out of your piercing.
10g through 6g can be difficult to work with. You will probably need to exercise patience, as it can require practice to get them in.
Please note: Glow-in-the-Dark items need to be "charged" in order to glow. Place the item in direct light (UV, Black Light or Sunlight work most efficiently) for several minutes, and afterwards they will glow for a limited amount of time. The brightness and persistence of the glow may vary.