Every home needs at least 1 Home Harmonizer Box, but some homes need an additional Booster Box due to higher EMF challenges caused by the following: 
 
Solar Panels/Power
< 100 Yards from a Cell Tower or SCADA Pole
< 25 Yards from XL Powerlines or an Electric Transformer (on pole or green box on the ground)
Home is over 4,000 Square Feet
Metal Roof
In a city/town with Military Bases or facilities