Each pack comes with:

• Venom Sticker
•  Plug Barrel bushing
• Matching durometer barrel bushing

These bushing are designed to remove lateral play in hangers by filling in the gap between the kingpin and the hanger hole.  

This has been a "as good as it gets" issue that has to the date only  been creatively solved by changing the geometry of the truck, adding additional metal pieces to force lateral stability, or some other "fix".  This solution however keep the truck working in a similar way, while really letting it's geometry shine through.