William K.wrote a review of Shimano SM-MA90 Disc Brake Adapter on October 3, 2016
Familiarity: I've put it through the wringer
Got the 180 post mount adapter. Essentially its a 10mm spacer used to increase rotor size by 20mm. Worked great with TRP HYRD to mount 160mm rotors on a Ritchey cross fork. Also used it to swap up from 160 to 180 front rotor on my mtb bike. Does what it needs to do.