Its from last year when I first got them installed. They are 18" resonated. I purchased this version because I live in a bit of a classy country club and the wife was not about me screaming everywhere I went. It gives me plenty of noise when I rev it up so im happy. I did however just order from Tony and FI some Resonated Test Pipes so it should increase the sound somewhat but Im happy overall. I get great compliments on my sound nonstop!