Vintage Loomcraft Darkest Blue Nylon Slip - Union made in USA
Color is very dark, like midnight blue or black. Fairly sheer
Size 34 M, check measurements: Measures 16. 5" across at bust. So 33" around with room in the cups.
28" waist. 37" hips. 38" long. Adjustable strap. Mannequin is 5'8" XS 32/25/34
Has a couple small rub marks on back, see closeup.

This item is sold from an excellent, highly rated vintage boutique.