Approximately 12inches long- darkest brown (almost black) color

I haven’t colored my hair in over 15 years, I blow dry and style flat iron/curling iron about a handful of times a year on average, or less. I wash it about 1-2 times a week. It is a very dark brown, some would say black, especially when wet. I do not use any product in it except moose from time to time when leaving it wavy/curly. It is very thick, and very soft/fine. I do not smoke cigarettes.
Picture of hair is taken on top of a paper towel that is 11 inches in length.