Selkirk RV Gas Pipe Wall Thimble is designed to ensure proper to combustibles while also serving as an effective firestop. This wall thimble adjusts from 4-1/8" to 7" to accommodate varying wall thicknesses, making it versatile for different installation needs. Made from durable galvanized steel, it is UL Listed and rated to withstand temperatures up to 550°F. Available in multiple sizes ranging from 3" to 6", each unit is crafted to fit specific wall thicknesses and vent sizes, providing a reliable and safe solution for Type B gas vent installations. This product combines safety, durability, and ease of installation for your gas venting requirements. Model Number: