I just picked up a brand new HKS Klasse Exhaust the other day and just recently installed it. A friend of mine just told me he is selling his tri flow to for $300, so I am trying to save some money here by selling My Brand New HKS Klasse. I bought it for $625 installed. Selling for $500 or best offer. I am in the Boston area so if interested, contact me. Remember, this exhaust is practically brand new(used 10 miles). Deep Idle, Smooth moderate loudness. Stainless Steel, with 4.5 Oval outlet. Very Nice looking Exhaust. Dyno proven 12 HP!