FlamingalsButt Lifting Leggings for Women High Waisted Workout Jeggings Cargo Leggings with Flap Pockets

How to choose its size?

Can you see through these leggings ?

If i wear a medium/large in peach skin leggings or a o/s in some brands what size would i order? the chart says. xxl? seems big?

Are these true to size?