Helps brow mapping much more faster and more accurately.***BONUS brows mapping video available after purchase.***FREE (1) Water Resistant Brow Pencil. Contact us via Facebook to upload the video. Facebook: "Brow Envy Microblading & PMU by Lindsey" or text to 774-243-2939. *ITEMS NEEDED FOR MAPPING-(as shown on mapping video and available for purchase)-Golden Ratio Caliper-Line Mapping Ruler-Ruler-Water Resistant Pencil-Surgical Marker-Razor to sharpen pencil