DuraVent 58DVA-IS Attic Insulation Shield Brand_Hot Spring and you can use them

and you can use them as replacement parts

For 18" opening or larger

This system combines the cleaning power of the FreshWater® III high-output ozone generator with MPS non-chlorine oxidizer and silver ions for protection against contaminants

Color: Black

Volts: 115

DuraVent 58DVA-IS Attic Insulation Shield Brand_Hot Spring and you can use themDuraVent 58DVA IS Attic Insulation Shield Overview Required for installations that pass through an attic to prevent insulation and debris from accumulating near the vent. Provides 1" clearance to combustibles. Includes base with tube, extension tube, and collar. What's in the Box 1 x DuraVent 58DVA IS Attic Insulation Shield Specifications Material: Galvanized Steel Diameters: 5" x 8" Brand DuraVent