* '''2015-07-21:''' '''Implemented''' as ranking reward
* '''2015-07-21:''' '''Implemented''' as ranking reward
−
* '''2022-06-08:''' Became '''improvable''' and '''upgradeable'''
+
* '''2022-06-08:''' Became '''improvable''' and '''upgradeable''' to {{Equipment/Link|15m Duplex Rangefinder Kai + Type 21 Radar Kai Ni + Skilled Fire Direction Center}}