A 28DD is small. VERY small. Its sister sizes are 30C and 32A. A

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Cosabella, Never Say Never Curvy Sweetie Bralette

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30C White Bralette, White Sports Bra, Workout Bra, Yoga Bra, Comfortable Sleep Bra, Supportive Bralette, Bra for Small Breasts, Convertible - Denmark

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