These flux or acid brushes are 6 inches long, with tin handles, and 3/8in wide, with 7/8 inch long horsehair bristles. Use these for a wide variety of industries and projects: acid/flux application or removal, apply wood glue in small areas, apply flux for rosin-care solder, add seam sealers to tiny corners and joins, apply tarnish removal creams, dab oil into squeaky hinges, grease up old machine parts, apply harsh chemicals without getting them on your hands, brush dust from delicate surfaces. Handles are comfortable to hold, and not long enough to prevent reaching odd, small spaces. Brushes are sturdy and long-lasting.