XS- Designed for women with a size 2 pant and no larger than a 30 bra size.
S- Designed for women with a size 4-6 pant and no larger than a 34 bra size.
M- Designed for women with a size 8-10 pant and no larger than a 36 bra size.
L- Designed for women with a 36 bra size and up.
The model in these photos is wearing a size M.