Pilot G2 Gel Pen

Pictured are:

1. The pen end and handle. 9.89mm in outer diameter. 8.06mm in inner diameter. 76.92mm in length, when the button is totally recessed.
2. The pen front. 68.00mm in length. 8.25 in outer diameter at the middle. 7.91 in outer diameter at the screw threads. 6.35mm in inner diameter.
3. The spring. It is 19.67mm tall, uncompressed. 6.36mm, compressed. 5.53mm in outer diameter, 4.54mm in inner diameter. The wire is 0.47mm in diameter.
4. The rubber grip. 1.3mm thick. 8.41mm inner diameter. 37.77mm in length.
5. The ink cartridge. It is 6.03mm in diameter. 110.47mm in length.  Filled with ink.

Why am I telling you these things?  Stay tuned…