This Rouxinol E-51 string set is for the Brazilian cavaquinho. It is made of stainless steel, the D and B strings are smooth, and the G and D strings have a nickel-plated tinned carbon steel core. End with ball.
The bass strings of the D'Addario EJ93 set have high carbon steel cores wrapped in stainless steel wire, so that the y respond well to the rhythmic patterns of the ukulele players. They are suitable for braguinha.