5" DuraVent DirectVent Pro Aluminum Low-Profile Vertical Termination Cap 58DVA-VC This vertical termination cap is used for vertical pipe terminations only. Check the appliance manufacturer's instructions to determine which caps are approved for use with their appliance. Provides combustion air and exhaust venting for gas appliances Clearance to combustibles mandated by appliance listing The components twist-lock together for a quick secure fastener-free installation 0.020" aluminum inner 0.018" steel outer Offsets venting obstructions .020” aluminum inner wall .018” galvanized steel outer wall Painted outer walls made of laser welded .018” galvalume steel. Caps also available in stainless steel and copper. Outer pipe brings combustion air to the appliance. Inner pipe exhausts flue gases to the outside. Gaskets or sealants not required (unless specified by the appliance manufacturer).