Specifically designed for PT88 turbochargers featuring a 4.0" V-Band outlet option Precision Turbo downpipe flange PTP074-3023 Specifically designed for PT88 turbochargers featuring a 4" v-band outlet option Discharge flange is optimized for use with 4" OD tubing The Precision Turbo 074-3023 V-Band discharge flange is specifically designed for PT88 turbochargers featuring a 102mm/4.0" V-Band outlet option. It/s important to note that the overall diameter of the flange face is 4-3/8" and the flange is optimized for use with 4" OD tubing. When it comes to your turbo installation, Genuine Precision Turbo & Engine V-Band Flanges are essential for ensuring optimal performance and reliability. Don/t settle for anything less than the best. Crafted from Mild Steel, these flanges offer a budget-friendly solution without compromising quality.