This particular version is the full DebonAir C1 Air Spring upgrade kit specifically designed Pike B1+ and Revelation A1+ forks 2018 and newer.
Rockshox has continued to raise the bar in how their suspension performs. That didn't change for the 2021 model year! Something that many riders has been looking for in the DebonAir damper forks was getting the fork to ride higher in the travel! Their new seal head and air spring have made some tweaks to really dial in where the suspension sits without sacrificing ride quality!
120mm & 150mm travel version.
Check your fork specs or check through Rockshox TrailHead