Vivid Exhaust Control Valve 2.5 Inch (63mm) 3 Bolt HondaSpecial fitment for Honda Civic, Prelude, Accord, Integra, Delsol, CRX.Reduces noise level of exhaust sound and controlable from inside of car. Is suitable to our Invidia, SIX, and Megan Racing catback applications or similair catback exhausts Diameter is 2.5" (63mm) 3 bolt (universal). Picture is for illustration use only and actual product might differ from picture. Installation between the catalyst and midsection. You can adjust the valve with a manual control handle IN your car (you can install this in your dashboard or console).Attention: Only fits if you catalyst-midpipe connection has 3 bolts, see second picture for details. Generally this is the right fitment for 99% of all Honda's with a catbacksystem from any brand.