Specs: Capacity: 3500 lbs Straight Spindle Tube: 2 3/8" Hub Face: 60 Spring Center: 48 Axle with 10 x 2 1/4" Electric Brakes (hub and drum incl) - 5 on 4 1/2 bolt pattern Bottom Mounted (underslung) EZ Lube (zerc in spindle for quick lubrication) used with double eye or slipper springs