These adapters make the Volvo S60R /V70N R front brake caliper together with the 354mm brake disc from the Nissan 370Z fit directly on your Nissan S13 /S14 /S15 /Skyline (not GTR) (S13 if you convert to 5-bolt)
NOTE! These products are not approved by Swedish car testing (as long as the car is not registered with them) and may therefore only be used on e.g. lane, ASS disclaims all responsibility for penalties you may receive in e.g. a flying inspection.
BUT! If you are going to inspect your car for registration with rebuilt brakes, these adapters are approved, what is normally required then is material spec and these are made of 10mm S355MCD.