The 34FF bra has a bigger band than the 34F bra. The 34FF bra has bigger cups and they are a lot deeper and wider than the 34F bra.
Helena White Balcony Bra from Fantasie
Comparing a Fantasie Smoothing Moulded T-shirt Bra (4510) with Fantasie Smoothing Moulded Balcony Bra (4520) in 30E
Advice - Bra Shapes Explained
Helena White Balcony Bra from Fantasie
34FF – Forever Yours Lingerie
Curvy Kate Victory Side Support Balcony Bra Poppy Red – Curvy Kate US
Advice - Bra Shapes Explained
Helena White Balcony Bra from Fantasie
Helena White Balcony Bra from Fantasie
34F - Panache » Andorra Full Cup Bra (5675)
Comparing a Fantasie Smoothing Moulded T-shirt Bra (4510) with Fantasie Smoothing Moulded Balcony Bra (4520) in 30E
34DDD - Wacoal » Retro Chic Full Figure Underwire Bra (855186)
Advice - Bra Shapes Explained