Foreign Trade Cross-Border Beard Filler Pen Kit, Waterproof, Sweat Resistant, Makeup Free Beard Pen Beard PenOur beard refill pen kit contains Brazilian palm wax, stearic acid. It lasts all day, is full of confidence, won't smudge or fade from sweat or rain, and will give you a perfectly contoured full look. How to use it is simple: First draw the outline and paint your beard or mustache evenly along the shape you want. It's waterproof, sweat proof and doesn't take off makeup.