Lennox MPB012S4S-1P is a high-efficiency mini-split heat pump outdoor unit rated at 12,000 BTU (1 ton) capacity for both cooling and heating. It delivers up to 23.5 SEER and 11.5 HSPF, runs on 208–230 V single-phase, and uses a variable-speed DC-inverter compressor for quiet, efficient performance. Built for single-zone setups, it’s compact (about 31.5″ wide × 13.1″ deep × 21.9″ high) and weighs around 94 lb. The unit features a pan heater to prevent ice buildup and supports R-410A refrigerant. It’s backed by Lennox quality and designed for easy, flexible installation — ideal for add-on rooms or spaces without ductwork.