The OTR 4" To 3-1/2" 12-Gauge Aluminized Steel Exhaust Connector is the perfect solution for your exhaust system needs. It is made from high-quality aluminized steel for added corrosion resistance and durability. The ends are de-burred and finished for safe handling and the notched ends make for easy installation where applicable. FleetPride is your First Click in Heavy Duty®.