Costway SUNDEAR MOON Manuel D'utilisation page 6

This heater is for use on 120 volts. The cord has a plug as shown at A in
Figure 68.1. An adapter as shown at C is available for connecting
three-blade grounding-type plugs to two-slot receptacles. The green
grounding lug extending from the adapter must be connected to a
permanent ground such as a properly grounded outlet box. The adapter
should not be used if a three-slot grounded receptacle is available.
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