Nioxin 3 part system kit no 4 for fine hair is an exclusive three tiered nourishing treatment system that has been specifically formulated to be used on fine and thinning hair whether it be male hair of female hair this unique three part system kit was one of the first products to come out of the nioxin hair care brand and its innovative formula will work to deeply nourish your scalp providing vital moisture and leaving you with the thick healthy hair that you crave the nioxin 3