Pierced at the usual 10ga 5/8 in straight barbell. It tended to shift from one side to the other, and pinch a little. Never wore a curved barbell. My favorite is my 5/8 inch cbr in 8 ga with a rather large 5/16 ball. Most comfortable, and ball keeps it in "centered" position, looks great.
Had a D ring, though like the bar it would shift from side to side, straight part would not stay up in the piercing as you'd expect, so it always hung crooked.
Also have worn a 1 1/4 cbr hoop or loop, think it is actually around 9ga, it's metric. That one was lot of fun, in the sun it shows through bikini swimsuits driving the ladies absolutely crazy, some hate it but many love it. My ridge is well defined, and am a "shower" so the large ring would mostly stay up on the top side when wearing underwear and walking around, though would dangle down when sleeping nude or skinny dipping or just plain cold.
At times it would be a bit much dangling around, as wanted it to stay on top all the time, needed some periodic adjusting, lol. Also you have to size a loop correctly to your body to allow for "growth". Know this is older post, so hope my comments helps you or others!