Injection-molded, high-temperature nylon built for harsh environments GEN4 brake blower flange mount adapter - 89mm/3.5" to 145mm The flange mount adapter is an add-on part for the GEN4 brake blower Injection-molded, high-temperature nylon built for harsh environments The GEN4 in-line reducer goes from 89mm/3.5" in the center body, up to 145mm at the exit duct. The flange mount adapter is an add-on part for the GEN4 brake blower. Injection-molded, high-temperature nylon built for harsh environments. Use case: For installation against a flat surface such as directly bolting onto a firewall.