Wheel Spacers？

[annyxu]

I see BONOSS wheel spacers have many new features, such as knurling, disassembly grooves, active cooling grooves.
Is there any quality difference between H&R wheel spacers and BONOSS forged active cooling wheel spacers?

[Jay762]

both TUV approved, both high quality AL so not much difference there.

WRT the cooling ducts, may work but I wonder how often you would need to be stripped and cleaned to remove the brake dust clogging up the grooves?