No leakage of ink, visible lines, writing smoothly and handy Package includes: you will get 20 pieces of 0.38/0.5 mm ballpoint pen replacement refills for retractable pens, 4.2 inch/ 107 mm in length; Sufficient quantity can meet your different writing, study and workdemands, and you can share them with your friends and classmates.Note: please confirm whether the size of this product matches your pen before purchasing Convenient to use: you can cut the length of the retractable pen refill to match a variety of pens, save your time and energy; They are portable and practical, if the refill's length is too long, you can cut its length to fit the pen case, finally install it into the pen case and you can use it Reliable to use: the shell of the retractable pen replacement refill is made of quality plastic, odorless and reliable, the ink inside is also adopts quality material, with color rendering and flows evenly, so the entire refill is reliable, allows you to write smoothly on paper; Note: please confirm the size of the refill and whether it is suitable for your pen before purchasing Nice performance: ballpoint pen refill comes with a 0.38/0.5 mm tip, allowing you to write or draw fine lines on paper smoothly and effortlessly, which are nicely fit for retractable pens, convenient for you to replace, useful for reducing waste, able to save your time for selecting other pens Applicable occasions: these pen refills are suitable for being applied at any occasions, including home, classroom, office, shops, and so on, enough refills of pocket size that is easier for storing; And can also be given to others as a gift