This small upright brush has 0.006" stainless steel wire and a hardwood handle. This handy brush style, also known as the keyboard brush, has a 2 x 6 row pattern, with a 1/2" trim, and a brush face of 7/8" x 5/16". The fine stainless steel wire cuts through heavy dirt or residue with ease and can often reach into fine crevices better than natural hairs and synthetic bristles. NB: Not recommended for use on circuit boards or SMTs as the stainless steel wire may cause unwanted scratching