Revlon ColorStay Brow Fiber Filler Eyebrow Gel in shade 301 Blonde is a waterproof, smudge-resistant tinted gel that builds natural-looking volume using microfibers to fill sparse brows. The dual brush-and-comb applicator evenly distributes color and fibers while taming hairs. Infused with conditioning avocado oil, it sets brows with flexible, long-lasting hold that resists heat, humidity, and flaking.