Bosch Wire Pencil Brush Steel Wire/Nylon Shank Ø 6mm - Bosch 2608622116, The wire pencil brushes from Bosch are supplied in sizes from 10 to 25mm and with either nylon or steel wire.
They all have a 6mm shank.
Bosch 2608622116 Wire Pencil Brush Ø 19mm Steel Wire 0.
35mm Shank Ø 6mm