ESD Brushes are ideal for removing dust, dirt and left over materials from printed circuit boards (PCB) and other static sensitive components. Brushes minimize static charge generation and remove electrostatic charges to ground when held by grounded personnel Dissipative polypropylene black handles are able to remove charges to ground Conductive handle’s ESD properties are not effected by humidity as are wooden handle brushes. Conductive nylon based copper bristles with hog hair and two other natural fibers. Better bristle flexibility and memory retention than pure carbon based bristles for extended brush life. Resistance of conductive fibers: 10E3 - 10E4 ohms Resistance of dissipative handle: 10E5 - 10E8 ohms Firm bristles are mainly for electronics, especially circuit boards This item is stocked in Chino, CA.