These are the two different styles of axle vent bolts used on Rear Axle's of Jeep Cherokee's & Grand Cherokee's. Both are 9/16 Head with threads that hold the Rear Brake Line to the Axle Tube.
#1 - Mostly Used On The XJs - They Have The Smaller Hose Barb
#2 - Mostly Used On The WJ's & ZJ's - These Have A Larger Hose Barb
