2009 Mitsubishi Lancer Evolution Shift Knob Size

I had no clue that shift knobs on manual cars were not one size fits all, and I was planning on getting my boyfriend a new one for his birthday, however I don't know what size to get. He drives a 2009 Mitsubishi Lancer Evolution and I was interested in getting him this shift knob (if that makes a difference).
http://www.hotrodshiftknob.com/vintage-jack-daniels-old-no-7-whiskey-shift-knob/
Thank you!