this is the pen you need to create Buster CYL. The back cap of Supertips has been removed. The dong a back plug has been wrapped with tape and carefully inserted. Both dong a caps are placed on each side.

The length is same or a couple millimeters longer than a double capped comssa. 

 Mod is Created by Spinnerpeem

  Example of completed Mod with Airfit Grips and tips: