Magnets will not damage your headphones in any way. The adhesive is a name brand 3M adhesive compound that should not damage nor leave any residue on any hard surfaces; however, should any damage occur please note that our policy is that we are not responsible for any damage caused by the adhesive or other parts of the ModMic. We do not recommend using the adhesive on fabrics and use caution when attaching it to polished wood or other lacquered surfaces.
Any excess residue left behind when removing the base clasp should be easy to clean off.