The Heroine Make Prime Liquid Eyeliner, Rich Keep, 01, Jet Black 0.02 fl oz (0.4 ml) Brush Tip, 0.0004 inch (0.1 mm), Domestic Ultra-fine Brush, Waterproof Formula, is a must-have for any makeup enthusiast, as it offers a waterproof formula that ensures long-lasting wear without smudging or fading, making it ideal for all-day use.