Bobbi Brown Perfectly Defined Long-Wear Brow Pencil has the following features: With a unique slant tip for ultra-precise definition, plus 16-hour wear that's sweat- and humidity-resistant and waterproof. Powered with a blend of waxes and emollients, this long-wearing formula won't smudge or fade, so brows look fresh and polished. Combs brow hairs into place, for a look that's flawless and natural with the attached brush.