HomeSaver 304 Alloy 11″ Guardian Cap – 3/4″ Mesh HomeSaver Guardian Cap, 304-Alloy,3/4″ Mesh. The Guardian caps are one of HomeSaver’s most popular caps and are available in both 304 and 316 alloy. They arrive fully assembled and secure with a tight friction fit with a 4 5/8″ collar that slides into the liner. Features: Guardian Round Chimney Cap. 304-alloy stainless steel construction with 3/4 mesh. Friction fit to inside of liner. Use with storm collar, top clamp, and top plate to complete system. Also can be used with a Collar Plate. Requires wind shields. Specifications: Overall Dimensions: 11″ (L).