Precision marking with refillable ink and a long nib design enables precise marking for deep holes, improving work efficiency. Enhanced performance: long nib with oil-based ink delivers smooth writing and precise lines. Waterproof and colorfast, suitable for indoor and outdoor use, including deep holes, making it a reliable tool for any project. Clean lines: the long nib provides controlled ink delivery with quick-drying and smudge-free performance, essential for architecture and engineering tasks. Portable and ergonomic: includes a sturdy cap clip and an ergonomic grip for comfortable handling. Easily fits in pockets or tool bags, enabling marking anytime, anywhere. Use scenarios: - Marking deep holes in wood, metal, or composites before drilling. - On-site layout and marking of construction drawings or architectural plans. - Marking outdoor surfaces during landscaping, surveying, or installation tasks.