1：Gel pen refill length 130mm,ink capacity large, long writing time, 100 black gel pen refills, 2 gel pens，refills can be changed at any time during work.【The refill is not suitable for Retractable ballpoint pen】 2 ：Gel pen refills black,be suitable for 0.5 mm ink refill replace , refill ink 0.5,are more reliable to use, have the advantages of ink pens and feel more comfo rtable in writing. 3: 0.5mm black ink refill has low viscosity, fast ink drying and beautiful handwriting lines,When it is used for the first time, it takes several turns to let the ink flow out. 4: The refill is made of highly breathable abc plastic, which is leak-proof. 5：MUST-SEE : 130 mm-long ink pen refills,Ink pen replacement refills,【These refills are not for retractable ballpoint pen with spring】Please pay attention to the style of refills you need before buying Gel pen refills, multipurpose refills, are more reliable to use, have the advantages of both ink pens and oily ballpoint pens, feel comfortable in writing, and have low ink viscosity. The pen holder has sufficient water, long writing time, no breakpoint, and the refill is made of highly breathable abc plastic, which is leak-proof. Always loved by students.