This deeply hole woodworking pen will improve the efficiency of their work Long head deeply hole marker pen provide carpenters with much more convenience 20mm long nibs marker is quick-drying, and can be applied for various surfaced such as-wood, metal, glass, and Multifunctional oil-based marker pen is suitable for furniture decoration, book shelf, lamp drill hole position for Waterproof marker pen with 20mm long nibs, which can be applied to marker deeply hole or wherever is hard to reach