Tein FS2 Coilover Suspension Kit - Model Y YL1YT Steering Wheels & Boss kits The D Series disc is

The D Series disc is designed as a premium OE replacement item

and the design has been completely redesigned

In the process

or for anyone desiring a better functioning gearbox with greatly improved reliability

reduced internal friction

Tein FS2 Coilover Suspension Kit - Model Y YL1YT Steering Wheels & Boss kits The D Series disc isDesigned for premium models, the FS2 features an external reservoir to allow for a larger oil capacity, greatly improving stroke and thermal dissipation. 2 way damping force adjustment offers 16 clicks of compression and rebound adjustment. With top mounts included, FS2 is complete bolt on package with everything necessary included in the box.