What after market oil filter fits a 1990 NC30?

Thanks in advance

Mahle OC31. Same filter as the CB600 Hornet, CBR600, early Fireblade and various other Japanese bikes of the era like the FZR600. Very common filter.

There are loads

Hiflo 303 and whatever others aere made to that standard. I used to use a Yam fazer filter as it was half height.