10" Drums suit electric brakes only. Use japanese bearings only as this type of bearing is best for a long haul.
10" drums are very stable and recommended by all major caravan manufacturers.
Ford Electric Drum
10 inch x 2.25 inch Drum
PCD = 4.5 inch
Thread Diameter = 1/2 inch UNF
Bearings = LM or SL
1000kg Capacity LM Bearings
1450kg SL Bearings