This is a classic style sold by Bali for many years in several different versions. See this earlier post for a another style. This is model 2612, the Sno-Flake Bow Bra by Bali. Judging from the ILGWU union label, it dates from between 1955 and 1963. It is strapless, with underwired, cut and sewn cups with light padding. Three back hooks. Good condition for it’s age, except for the powernet wings are a bit stretched out.