NukaTap FC Gen 1 to Gen 2 upgrade kit.

Auto-Close Spring Compatibility
If you prefer using an auto-close spring. The previous Auto-Close Spring no longer works with the Generation 2 Flow Control NukaTaps. You must use this auto-close spring with the NukaTap FC Gen2’s – NukaTap Mini & NukaTap FC Gen2 – Self Closing Tap spring

Check the photo below, Please note the o-ring is included on part 12 already. A small amount of lubrication may be required.