Perfect for applications with limited space. If you want to lower the sound pressure level (SPL) of your CrateMuffler(r)s, you can install this resonator. This compact bottle / bullet style resonator can also be used as a universal resonator in any system of this diameter. The Resonator is designed to attenuate overall sound. This is perfect for customers looking to reduce the sound level 2-3 dB(A). This straight-through design will not degrade the performance of your vehicle. Resonator dimensions 2.5" Center Inlet/ 2.5" Center Outlet, 4" Round, 10" Long Body 15" Overall Length. Un-Notched necks are designed for weld in installation. If clamping, use 3" wide band clamps 18004. Reversible design for installation flexibility. High-quality T-304 austenitic stainless steel for superior corrosion resistance. 100% welded construction for strength. Free Flow design for improved performance. High-temperature continuous-filament fiber (CFF) acoustic material for sound control. Natural mill finish can be brushed or polished prior to installation. There is no logo embossment on this part. Best of all, it's made in the USA and backed by BORLA(r)'s Million-Mile warranty. Just what you'd expect from the world's most experienced (and most winning) exhaust brand.