Bevknits #4003, vintage sewing pattern, dated circa 1970s.
Women's Power Net Girdle.
Sizes Small (8-10), Medium (12 - 14), Large (16 - 18) and Ex Large (over 18) included.
Pattern is an uncut, large format master pattern, with sizes S, M, L and XL included. Trace your size off the paper master. Pattern has some handwriting in places, will not affect use.
More vintage lingerie patterns here:
https://allthepreciousthings.com/collections/underwear-and-lingerie