1. Diameter and length of refill: Generally speaking, the diameter and length of refill are the main basis for indicating the model of refill. For example, the diameter of a common gel pen refill is about 4.5 mm, and its length may be 1 10 mm, 1 15 mm or 130 mm. ..
2. Flange diameter and refill length: Flange diameter and length are also important parameters to indicate refill model. For example, the outer diameter of the flange of a common gel pen refill is about 6.5 mm, and the length from the flange to the pen tip is about 15 mm. ..
3. Mouth diameter of the pen tip: For the needle tip, the mouth diameter is also an important parameter, usually about 2.5 mm. ..
The above are the common methods to check the model of the push pen refill. The specific refill model may vary according to the brand, type and size. If you need more specific information, please refer to the instructions on the refill package or contact the manufacturer for consultation.