Mechanical, Refillable Marking Pencil that writes on any non-porous surfaces, such as metal, acetate, plastic, glass, and even photos Wax lead is non hazardous and non-toxic making it safe to use in both industrial and households Unlike peel-off china markers, these mechanical pencils can be used fully (no wastage) and can write on wet and damp surfaces Easy to wipe off with cloth and a tiny bit of window cleaning spray or use a little water and some elbow grease Used extensively in restaurants to write on packages and plastic glasses; construction industry to mark on tile, wood, metal, concrete etc; households to mark on freezer bags, milk storage bags, general storage boxes and many more uses