This 304 stainless steel header collector reducer kit is designed for builders, fabricators, and performance enthusiasts running custom exhaust systems. The collectors feature a standard 3 inch 3-bolt header flange inlet reduced to a 2.5 inch or 2 1/2 inch exhaust outlet, making them ideal for adapting performance headers to smaller diameter exhaust piping. Each collector measures approximately 3.5 inches (3 1/2 inches) in overall length, allowing for easier fitment in tight spaces where longer collector reducers may interfere with chassis components or exhaust routing. The compact design makes these well suited for custom exhaust fabrication and performance builds. The collectors are constructed from 18 gauge 304 stainless steel tubing with an approximate wall thickness of 0.05 inches. This material provides excellent resistance to corrosion and heat, making it suitable for high-temperature exhaust environments and long-term use. This kit includes solid copper 3-bolt collector gaskets, a key upgrade over typical composite or fiber gaskets. Copper gaskets are commonly preferred in performance and custom exhaust applications due to their ability to handle high exhaust temperatures while maintaining a consistent seal. The 2.5 inch outlet is designed for custom exhaust connections and may be welded or clamped depending on the installer's exhaust configuration. These collectors are intended for universal applications using standard 3 inch 3-bolt header collectors. What's included in the box: ● Two 304 stainless steel header collector reducers ● Two 3-bolt flanges ● Two solid copper 3-bolt collector gaskets ● Mounting hardware included Fitment note: Designed for use with standard 3 inch 3-bolt header collectors and 2.5 inch (2 1/2) inch exhaust systems. Intended for custom exhaust applications. Professional installation is recommended.