Techspray usa flux pen the no, Clean flux dispensing pen is intended to dispense no clean flux in high precision functions like prototype and rework/repair of printed circuit boards. The resin and halide free no, Clean flux will leave no residues. It provides optimum wetting across an extensive variety of surfaces and will not damage commonly used plastics. Excellent wetting abilities, Pen tip allows accurate application, Excellent for surfaces with poor solderability.