3-1/2" ID Venair Silicone Coupling, 3" Long, 4 Ply Polyester, Black Item ID: VACPL4P-3503-BLK Wall (spec): 4 Ply Polyester Reinforced Temperature Rating (spec): -76F to 356F (-60C to 180C); Material (spec): Silicone Length (spec): 3.00" (76mm)