Hubs have studs pressed into them. They have a 5" x 5 1/2" bolt pattern. They are for use with original or reproduction 1940-48 style "slip-over" drums (21A-1125 or 21A-1125-F). The front hub includes both bearing races and a dust cap. You will need bearings B1201T & B1216T. 
USA made.
Drum mounts to front side of hub, used with our 21A- series brake drums.