Confused on naming of gauges

[Bishop]

i got my ears pierced in July and I'm up to 9/16th currently, so I'm still relatively new at ear stretching. This may be a real dumb question but I why this gauge is named 1/2"g 5/16.
http://www.amazon.com/Stainless-Steel-S ... 166&sr=1-1

[shellbournian]

1/2" is the gauge (diameter of the cylinder) and 5/16" is the wearable area (the distance between the flare and the o-ring, NOT the total height of the cylinder)

You can't really get plugs with too "big" of a wearable area, but you can definitely get them too small (squeezing your lobes makes them itchy and irritated).

5/16-3/8" is pretty much the "medium" of wearable areas, but you should measure your lobes to get a good estimate and experiment to see what works for you.