This is an addon wheel mod You need the Thrustmaster T300 parts in Photos
The added buttons and dials are  COSMETIC and  can be placed anywhere giving a more custom design, wheels functions will remain the same.. 
Grips are installed with Alcantara padding.
Formula style. Open Wheel  GT3 mod for Thrustmaster T300 RS / GT
Wheel size 280mm all bolts included included.

Printed with laminated carbon fiber infused plastic for ridigity and beauty.
Grips pre installed only needs to be bolted to the Thrustmaster T300 wheel base.
For instalation guild search YouTube for Thrustmaster T300 open wheel mod many videos available.
 
 Thrustmaster parts shown in photos are not included