Benefit Cosmetics Mighty Fine Waterproof Brow Pen 2-pack What It Is This super-fine brow pen by Benefit draws on three superfine lines in one stroke, so you can get fuller-looking brows with a longwear formula.   What You Get (2) .01 oz. Mighty Fine Brow Pen What It Does 24-hour longwear Waterproof and sweatproof  Smudge-proof  Transfer-proof How to Use Shake, shake, shake! Hold the brush perpendicular to brows to get the finest lines. Flick upwards onto clean, dry brows. Hot Tip: Every so often, wipe brush tips gently across a clean tissue to keep them in tip-top shape.