SPECIFICATIONS FHA PIPE FLASHING #RJ3FHA 26 Gauge Galvanized Steel • For 3 inch exhaust pipes 3 ½ in. 8.9 cm HEIGHT 3 ½ in. 8.9 cm 20 ½ in. 52 cm 17 in. 43.2 cm 7 ½ in. 19.05 cm 6 in. 6 in. 15.24 cm 15.24 cm 6 in. 15.