Ordered quite a few of these over the last year, and they hold up well in the wash and dryer. Super comfortable and suitable for any workout. Not see-through. My favorite pair of leggings by far. If you weigh under 130 lbs, I'd order an x-small! Or a small, if you want a loser fit. I've ordered both XS and S sizes and they fit almost the same on me.
Update: As of August 2020, I've ordered a couple more of these leggings and the fit and material have completely changed. The price went up and the quality had gone down.