A club steak (aka wing steak) is smaller than a T-bone or porterhouse steak, and rectangular shaped (in some regions, it is a triangular cut.) It is basically a strip steak, but, it will have a rib bone in it.
Despite that, some people treat club steak as just a synonym for strip steak, though a club steak has a bone, and strip steaks are always boneless.
Club steak has the same flavourful eye section as does the T-bone, but unlike T-bone or porterhouse steaks, has no part of the tenderloin in it.
They will be about 350 to 400 g each (12 to 14 oz).
Choose ones with fine grain and good marbling.
Jordan, Harry. Meat Harry. Renfrew, Ontario, Canada: General Store Publishing House. 2003. Page 14.