1.Advanced Ballpoint Pens have obvious trademark grades and model marks on the pen case, and there are also obvious grades, production dates and "Da" markers (the "Da" Mark is the combination of the first letter of the Chinese pinyin of the file two words) at the tail of the refill.
2. Must be equipped with metal tubing refill, pen head beads must use cemented carbide-tungsten carbide ball beads, writing performance is better than the general ballpoint pen, perfusion in the pen core ink must use fixed-point production of 424 pure blue ink and 322 black ink. These two kinds of ink, with sun-resistant, water-resistant, non-seepage advantages.
With these two kinds of ink perfusion of the ballpoint pen core, can be used for file writing (including plastic tubing refill, but the color of the tubing must use light yellow tubing).
3. In the packaging of goods, there are trademark grades, models, production plant name, origin and quality inspection certificate and other signs, marks. Fake and shoddy goods, refill of the ink is not approved by the National Archives of the file ink, in the pen core there is no "DA" mark, there is no trademark grade, model, factory name, origin, some with foreign smuggling into the unlicensed refill, assembled into an imported advanced ballpoint pen.