Inception Designs Genesis Barrel Back for PWR insert Color:Matte Black Tune Assist The APE OLED Proton Case Tune Assist The APE OLED board features a new semi automated “Tune Assist” feature that allows users to quickly tune their marker for peak efficiency and speed by providing quick adjustment of both solenoid dwell and bolt return timing giving the user a real world training tool or backyard plinker They are marked with bore sizes that can be easily seen without removing the insert from the barrel back (and can also be identified by the color as seen through the rearmost ports on our barrel front The design of these new PWR inserts is different to those you are previously familiar with