--360mm to 390mm rotor upgrade spacers--
The bolts are the key item in keeping the caliper attached to the car, and they are what's important for strength since the load is in shear. The spacers could be 3d printed PLA if they could handle the heat and function perfectly.
But hey, marketing so you can charge people $100+ for some laser etched washers no one will ever see.
He's offering a product that he makes, which makes the 390mm rotor upgrade much easier...if you don't want it you don't have to buy it...but your demeanor, tone, and verbiage comes across like you are personally insulted...








