Whistler HIGH SURGE POWER INVERTERS Owner's Manual page 6

WHISTLER FEATURES
A Word About Whistler Power Inverters
Whistler inverters convert low voltage, direct current (DC) to 110
volt alternating household current (AC). The AC output is called
"modified sine wave". See "Technical Operating Principles"
section for more information. Depending on the model and its
rated capacity, Whistler inverters draw power either from standard
12 volt automobile and marine batteries or from portable high
power 12 volt sources.
Inverter Feature
1200 watt series shown
3