Never been worn Knix bra. This is a size 5 which is the equivalent of a 36D or 38C or 38D or 40C according to their sizing (see last image). However I found that this style runs a little small in the band. Product Description From their website Our best selling bra, now available in 99 sizes for a custom-feeling fit. The WingWoman Bra provides shape and definition without compromising on comfort. Wire-Free Support Lightly padded, molded wireless cups create lift and separation. All Day Comfort Provides shape and definition without compromising on comfort. Feels Made For You Available in a wide range of sizes with adjustable straps and a 5-row back closure for a custom-fit feel. Smooth Coverage Extra coverage on the side and back creates a smooth silhouette that eliminates sideboob spillage.