These XAF series are MaxAlloy aluminum indoor coils and are designed to be installed with furnaces and modular blowers to be matched with cooling and heat pump outdoor units. All indoor coils shall be applied with TXV which are required for system ratings with certain outdoor units. Refer to the Technical Guide for the outdoor unit selected as part of your system. Coils maybe provided as "Flex-coils" without a factory installed metering device or factory installed TXV. For added application flexibility, a R410A TXV is field installed on "Flex-coils" to meet your needs