Hisense 3 Series User's Operation Manual page 25

The appliance must be installed on a solid and level floor surface (if necessry
use a spirit level). If the appliance is to be installed on a wooden floor, distribute
the weight by placing it on a 60x60cm sheet of plywood at least 3cm in thickness
and secure it to the floor. If the floor is uneven, adjust the 4 leveling feet as
required; do not insert pieces of wood etc. under the feet.
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