Talk:Setsubun/@comment-27811420-20200205215323/@comment-26082284-20200206185952

Some more advanced equipment require them: Iserockets, 41cm K2s (twin and triple), D guns, concentrated mortars... But most importantly, quite a number of K2s require them, including Yuugumo-class or, recently, Melon-chan.

They aren't that hard to obtain, but they see a lot of use.