4" X 6-5/8" DirectVent Pro Counter Flashing 46DVA-CFK This counter flashing prevents water intrusion into stucco-sided homes. Allows the installer to apply siding material (i.e.: stucco brick etc.) over the flanges up to the sides of the flashing for a water-tight seal. Kit includes 4-pieces; sized for Square Horizontal Cap only. 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).