Just twist & comb. Eliminating grays is as easy as combing your hair. With Just For Men easy comb-in color one tube of our patented no-mix formula meets one specially designed comb applicator. Just twist & comb it in. Give it 10 mins to blend away the grays then wash it out for a natural gray-free look. Great for targeting gray areas or covering grays throughout your hair. Lasts up to 8 weeks until grays grow back. Can t decide between two shades. Try the lighter one first. You can always go darker later.