Mitsubishi 42,000 BTU multi-zone outdoor heat pump (MXZ-5C42NA). This is an extremely efficient unit that can connect to a variety of indoor unit types and can handle three zones (indoor units).

Unit Type 3.5-Ton Inverter Condenser Heat Pump
Product Line M-Series
Operating Mode Cooling & Heating
Low Ambient Heat: NO
Number of Zones 5
Unit Capacity 40,500 BTU

Outdoor Unit MXZ-5C42NA

Cooling Capacity up to 43,000 BTU
Heating Capacity up to 53,600 BTU
SEER2 Up to 19.7
EER2 Up to 9.2
HSPF2 Up to 10.3
Heating Minimum Temp 5 F
Cooling Minimum Temp 14 F

This outdoor unit allows you to connect a wide variety of indoor units ranging up to 53,300 BTU.
Blue Fin anti-corrosion treatment applied to heat exchanger for increased coil protection and longer life.
The outdoor unit powers the indoor units, and should a power outage occur, the system is automatically restarted when power returns.
Quiet outdoor unit operation
Intelligent Power Module (IPM) for reduced power loss
High pressure switch for additional protection