H&M conscious exclusive jacquard dress

Absolutely new,tag removed but never worn,and always kept in garment bag since I bought it directly from H&M website. I have ocd when it comes to clothes🤣, so all my sensitive material dresses,leather jackets ,coats,blazers are always in garment bags. Size is 10 but it definitely fits two sizes smaller. Pit to pit measurement is 16 inches. I will mark the listing as size 6.