This is the brush that employs infrared and blue light waves to minimize dandruff and rejuvenate follicles for thicker, healthier hair. With each stroke, the infrared 660nm and blue 470nm wavelengths stimulate the scalp to boost blood flow and reduce unsightly flakes of dandruff. Effective for men and women, it uses the same low-level laser therapy (LLLT) that has long been demonstrated in clinical trials to be an effective treatment for hair loss. Two modes of operation include gentle massage to promote circulation to the scalp. Replaceable and washable nylon bristles. Requires two AA batteries. 9" L x 2" W x 1 1/2" D.