These Soldering Iron Sponges are ideal to be used as replacements for old sponges. Use to keep your soldering tip clean. Moisten slightly before use. When it wet water will be inflate, welding time soldering iron will have the solder and the residue , the sponge makes the cleaning action Strong absorbability Help on the tin and antioxidant Endurable Material: Sponge Color : Yellow Use for: Remove solder residue, maintain PCB components clean. Notice: Please soak the sponge in water before use!