View source for Noctua NH-U12DO A3

Released some time before Mar 15 2011<ref>https://forums.tomshardware.com/threads/new-noctua-heatsink-noctua-nh-u12do-a3.341631/</ref><!-- more detailed research on release date could be done --> It is now discontinued<ref>https://noctua.at/en/nh-u12do-a3</ref> since some time after Nov 24 2019<ref>https://web.archive.org/web/20191124092237/https://noctua.at/en/nh-u12do-a3</ref> but after Dec 06 2017<ref>https://web.archive.org/web/20171206163252/http://noctua.at/en/nh-u12do-a3</ref><!-- more detailed research needed on when it got discontinued -->