Microfiber Nylon Spandex Seamless wireless bra- No hooks clasps or wire Back is Smooth Extra wide fixed bra straps Nylon/Spandex fabric blend Small Bra fits- 30A to 34D Medium Bra fits- 34A to 36D Large bra fits- 38A to 42D Extra Large Bra fits- 42A to 48D/DD