3" actual flex joint on mine... Size matters! But in the spy world, it's reversed... They do decrease engine vibration! The first test pipes I made were solid and that thing BUZZZZZZZZED like a mutha!!!

http://www.bnmotorsports.com "And I will strike down upon thee with great vengeance and furious anger those who attempt to poison and destroy my CEG brothers. And you will know I am the Moderator when I lay my vengeance upon you."