DescriptionReviewsBON-102 - Solder Paste Flux Cleaning Brush / Pen for PCB Board The soft brush tip will never harm the PCB board copper foil or IC pin. The pen tip releases flux and the liquid flow is moderate. This pen is empty, you can fill it with flux, and alcohol. Easily clean the pen after inhaling alcohol. Translucent body design, can clearly check the amount of residue.