Flange is 3.75 OD and 304 stainless.
2.5" 3-1/8 OD v band flange .065 304 stainless tig welded turbo exhaust
3" OD to 3.5" OD Aluminum Reducer Fit Universal Piping 3.65" Length
3" OD to 3.5" OD Aluminum Exhaust Pipe Reducer Fit Universal Piping 3.65" Length
K&N 85-1160 Adaptor Reducer 2-1/4"ID 2-3/4"OD 2"L ADAPTOR 2-1/4"ID 2-3/4"OD 2"L
4" OD to 3.5" OD DIY Aluminum Universal Reducer 3.9" Length
2PCS 25FT 3/16''OD&1/4''OD Coil Rolls Copper Nickel Brake Line Tubing Kit (USA)