ActronAir Indoor Evaporator Fan Blower 9x7 1/2HP ECM brings variable-speed ECM technology to the compact 9x7 blower format, enabling precise fan speed modulation on smaller-tonnage ESP Plus and Classic Series indoor units. The 9x7 ECM blower is physically smaller than the 10x8 and 10x10 ECM variants -- do not substitute a larger ECM assembly as the impeller-to-coil clearance geometry will be incorrect. Isolate power at mains before replacement -- live work on fan assemblies is dangerous and must only be performed by a qualified technician.