Steel = Brass-plated steel wire - Excellent for cleaning in hard-to-reach areas, e.g. angles or corners, pipes, etc.- HBG = Scratch bruches, curved type Ideally suited for cleaning work in hard-toreach areas e.g. angles, corners and pipes.Steel = brass-coated steel wire HBZ = Scratch brushes for spark plugs Ideally suited for cleaning spark plugs, small workpieces and tools.HBB = Scratch brushes/block brushes Ideally suited for cleaning and rust removal on surfaces.HBF = Scratch brushes for files Suited for cleaning files.HBFM = Scratch brushes for precision mechanics Ideally suited for light cleaning work on fine surfaces.The filament diameter of 0.15 mm allows a smooth brushing action and produces a smooth surface.Ordering example: EAN 4007220153727 HBG 10 ST 0.30 Please complete the description with the desired filament material and filament diameter.