Last Sun Underwire A bikini with a sunny outlook on life. Part of the special edition collection with lifestyle and fashion blogger, Sincerely Jules, the underwire bikini top is trimmed with playful pom poms at the front and finished with crisscross ties that lace up at the center back. Solid underwire bikini top. Pom pom trim. Adjustable straps that crisscross and tie at center back. Solid. Billabong x Sincerely Jules Collection. 87% Polyamide13% Elastane.