For Jeep Grand Cherokee/Wrangler 6-1 Design Stainless Steel Exhaust Header Kit (Silver Ceramic Coated) - YK TJ XJ ZJ Application: 91-99 Jeep Wrangler/ Cherokee/ Grand Cherokee 4.0L 6-2-1 Design / Bolts to OEM Exhaust 1.5" Inlet / 2.125" Outlet TIG Welded CNC Machine Flange Increase High Flow Air, Instantly Gain 10 -15 Hp. / Tq.