The RectorSeal 83017 Flexible Wall Sleeve is designed to provide a reliable seal when penetrating walls, ensuring that duct installations are secure and efficient. It is suitable for use with various duct systems, especially mini-split condensate drain hoses. The sleeve features a corrugated construction for greater flexibility and is intended for interior use only to prevent crimping. The telescoping design extends from 4" to 7.5" to fit various wall thicknesses, and for walls thicker than 7.5", two sleeves can be joined to create custom lengths. This product ensures professional, neat, and durable installations.