Isomars Brush Pen Set of 3 includes 3 brush pens with nylon brush tips and refillable reservoir . 1 Small pen size: hair length: 1. 4cm 2. Medium pen size: hair length: 1. 6cm 3 .Large pen size: hair lenth: 1. 7cm. Have fine tips for details, round brushes for whole layout, flat brush for broad strokes and filling. These paint brushes offer long-wear and excellent color control with brush strokes. Filaments hold color and release smoothly and evenly.