Rinnai 224077PP - 45 Degree Elbow - Condensing Tankless Water Heater Venting - 3" / 5" - 2 Pack Ubbink Polypropylene concentric venting delivers a professional solution with improved safety and convenience. Features For use on Rinnai CONDENSING appliances only. Do not combine the vent components illustrated on this page with any other vent components. Material of Inner/Exhaust - Polypropylene, Flame Retardant (ULc S636 Gas Vent-BH Class IIC 110 degrees C/ 230 degrees F) Material of Outer/Combustion Air - Plastic. Vent components consist of an outer plastic vent for air intake (5" diameter) and an inner polypropylene vent for the exhaust gases (3"diameter). Refer to the Rinnai installation manual and the Ubbink installation instructions for complete installation details and requirements Item Number: 224077PP Rinnai Product Category: Vent Elbow 45 Product Series: Ubbink 3x5 US-CAN UPC Code: 8713645131993 Product Weight: 0.55 lbs Shipping Dimensions: 11.5" x 6.5" x 6.5" Shipping Weight: 1.60 lbs / (0.73 kg) PRINN10325