Designed to provide the best technology to equalize pressure between indoors and outdoors, while providing effective ventilation for a cleaner, healthier home Replaces the Pressure Switch inside these product numbers: MD6TU, MD8TU & MD10TU Replaces OEM # S97018853 Designed to provide the best technology to equalize pressure between indoors and outdoors, while providing effective ventilation for a cleaner, healthier home. Replaces OEM # S97018853