This is a Step Down Racing Wheel Hub with Quick Change Bearings
Product Specs:
Front Wheel Hub – Step Down
Bearings are slip-fit / quick change (not pressed in or held by retaining ring)
High Speed Inside Bearing – 1 5/8″ OD x 3/4″ ID
High Speed Outside Bearing – 1 3/8″ OD x 5/8″ ID
Oval width: 2-3/8″ (Offset: 3/4″ bearing side 1″ wide, 5/8″ bearing side 13/16″ wide).
2-1/2″ Bolt Circle
(3) 1/4-28 Bolts