ONYX Racing Products 32- Hole 12 mm Thru x 150 mm, 12 mm Thru x 157 mm 6-Bolt Disc Bicycle Rear Hubs
The hub drilling is the number of spoke holes. It must match your rim spoke count.
This is hub spacing and is the width of the hub. It must match your frame specifications.
This should correspond to the type of brakes you have on the bike.