I bought a similar kit from Slime for about $25If you are changing from RFT to Normal Tire
In my 2002 M3 I had a similar kit furnished by BMW, it served me well. Once my RFT need to come off I will change to PS2. And get myself a Conti Comfort Kit. Just sharing this information with you Fellows.
For a write up go here
There is even a cheaper kit for less than $20