The stock JK front driveshaft has a U-joint on the axle end and a booted CV on the transfer case end. Much like J.E. Reel's rear shaft, this front version has a U-joint on the axle end and a double-Cardan joint on the T-case end. It's not a mandatory upgrade for lifts lower than 4 inches, but it's much more heavy-duty and will last longer than the factory components, so we think it's a worthy upgrade. No pinion angle adjustment is needed. The J.E. Reel front driveshaft simply bolts in place of the old one.