Comparing a 30G Freya Hero Side Support Plunge Bra (1841) with a 30GG Freya Hero Side Support Balcony Bra (1842)
The band is pretty much the same in both bras. The 30GG bra has bigger cups and they are a lot deeper and wider than the 30G bra.
The 30G is 1 cup smaller than the 30GG.
Hero Side Support Plunge Bra (1841)
Hero Side Support Balcony Bra (1842)