Name Writing Power Engraving Pen Etching Carving It Name Machine for All Glass Metal Plastic Wood, White, Set of 1 It works with wood, steel, bamboo, metal, acrylic, glass, and plastic. Customize and personalize anything you want - including cups, teacups, shot glasses, keys, keychains, belt buckles, phone cases, sunglasses, containers, and much more... Unscrew Engraver Pen from the bottom section by turning counterclockwise. Insert the battery with (+) side facing up (AA-size). Hold Engrave pen just like a normal pen, with a thumb over the control button... Press the control button with thumb; apply slight pressure and press the tool down on the surface to be engraved; hold at a slight angle. Turn off when finished by releasing pressure from the control button