Ohlins Complete Air Spring Cartridge Assembly - 160mm For RXF38 m.2 ForkThese complete air spring cartridges for Ohlins forks feature their three chamber air spring system with two externally adjustable springs: adjust the main spring by adding air into the top valve and control the progressivity by changing pressure on the bottom of the fork of the ramp up chamber. The third chamber is the negative spring which can futher be customized by removing or adding up to two volume spacers.