The one on the left. Killeen/Ft. Hood and surrounding area with 250,000 people here, and NOBODY has it! I've been to Home Depot twice, even sent my dad there looking for it, went to Lowes, Ace Hardware, Killeen Propane and Hardware, and even asked my buddy who's a plumber and he can't find one. WTF?? It IS 5/8" right? Is that inside diameter? Cus I tried a 3/4" ID just for kicks and giggles and it was too big. I can't find one for the LIFE of me, and I NEED IT BAD!! HUGE EXHAUST LEAK!! Car's running pig rich and bucking because of it. It made my g/f sick the other day cus of the fumes. I am NOT gonna pay freaking $20 for some stupid wazee cap. SOMEBODY has to have one other than them! HELP!!!