They are the identical sychronised swimming twins who do everything together and even having match boob jobs.
And Bia and Branca Feres will be hoping their closeness will help them out as they go for gold at the Olympics for the host nation Brazil in the sychronised swimming team event.
The sisters, aged 28, are celebrities in their native Brazil and win or lose at the Games, they have a string of modelling and TV presenting jobs lined up for after the competition.
They caught the nation's attention after posting a series of very revealing and sychronised Instagram pictures, showing their lives together.
This includes working out together in the gym, practising their sychronised swimming routines and even sleeping together in the same bed at night.