Purchased blue, red and black together with the white board. I thought that the ink is cartridge-replaceable and economical.
Because it is medium-sized, it's nice to write even small kanji. If possible, I think that it is okay to attach a magnet as it is optional.
Since only the cartridge of this product was in the company, I repurchased the main body. It seems that I threw away the main body because I tried other products as well. The cartridge is economical, but it is totally overwhelmed if you throw away the main unit. The feeling of use is good.