Just For Men Mustache & Beard Color in Medium-Dark Brown (M-40) is a specially formulated facial hair dye that provides natural-looking coverage for gray facial hair. This easy-to-use coloring system is designed specifically for coarse facial hair and delivers consistent results in just 5 minutes. The product comes in a kit containing everything needed for multiple applications. The formula is specifically designed to work effectively on coarse facial hair while being gentle on skin. The Medium-Dark Brown shade (M-40) provides a natural-looking color that blends seamlessly with existing facial hair. For best results, perform a patch test 48 hours before use and follow all included instructions carefully.