3.5K. 4" Dropped axle. 2 3/8" diameter. This is the axle only. Hubs, mounting kit and springs sold separately. There is a $15 set up fee and shipping is EXTRA. If ordering multiple axle components (hubs, springs, etc.), the $15 drop ship fee from each component will be applied to shipping and deducted from second invoice. Estimated shipping is $35 to $50. Ordering for a Mullins? Choose the 56"