Kosas Brow Pop Nano in Medium Brown. Kosas Brow Pop Nano in Medium Brown. A longwear, ultra-precise 1 mm pencil for the tiniest hair-like details and a clean, soft natural look.. In Medium Brown - neutral medium brown. Formulated without fragrance, silicone, or mineral oils. Vegan and cruelty-free. 0.03 g/ 0.001 oz. Using the spoolie, brush brows up to groom. Twist up nano tip until just visible.. Without pressing hard, use a gentle flicking motion to softly detail and add dimension.. KOSA-WU237. 26_03. Makeup for skincare freaks. Sheena Yaitanes created Kosas in 2015. It's quick, easy, really-works makeup that also doubles as skincare - packed with clean treatment ingredients. Because taking care of your skin includes the makeup that you put on it.