This "casual" outfits are worn by Samus Aran in the best endings of the classic Metroid games. The outfits were featured in Metroid II: Return of Samus and Metroid III/Super Metroid, although Samus had also worn the Justin Bailey in Metroid I, this tank top and panties are exclusive to the first 2 sequels.
Both skins are to be used on the c06 and c07 slots exclusively.
This mod also includes a variant for the Metroid II one without the rocket boots/heels for a more accurate look (and that Ellen Ripley kind of feel).