Two versions: as a top and as an accessory (you can have both). The accessory one gets that stupid salmon-colored bra over it when you remove the sim’s clothes, so that one’s only to wear under other tops or dresses (the thumbail’s a bit weird, a pair of tights methinks). You can find it in the leggings category, and the top with brassieres.
Both versions come in black, white and a bright pastel pink, and they’re for everyday, formal, sleep and party. With the bright ones you can choose between white or black bra underneath. I think teen to elder, but I forgot to check, sorry ๑•́ㅿ•̀๑