Anden dehumidifiers are designed for maximum growth. The 5771 Multi-Pleat 11 is produced with a highly specialized, dual layered 100% synthetic media, specifically for use in Anden dehumidifiers. The Anden 5771 is composed of an upstream electrostatically enhanced layer (the E-Layer), and a downstream mechanical layer (the M-Layer). This replacement filter is easy to install, with no assembly or reinforcements to worry about. Protect your equipment for optimal performance.