The Selkirk 4RV-90 Adjustable 90 Degree Elbow Type B Gas Vent is a versatile HVAC connector designed for various applications. Made of galvanized steel with a 1/2 inch thickness, this round elbow duct has a 4 inch diameter and is flexible for easy installation. It is compatible with packaged rooftop air conditioner units, central furnaces, packaged rooftop furnaces, whole house air conditioners and heaters, and central air conditioners. With a maximum pressure of 0.4 psi, this 6 inch long connector is lightweight at 1 lb and features a silver hose color, making it a reliable and efficient addition to your HVAC system.