Premium Cube model comes in carbon black alloy. One Cube is recommended per home or office with high EMF. Homes or offices within half a mile or line of sight of a cell phone tower, smart meters or a large number of Wi-Fi routers are good candidates for the Premium Cube. It provides coverage of 90m in all directions. The new multi-wave scalar waveform configuration in our Premium Cube offers the best protection to date from radio frequency radiation and 5G. Some people may experience a minor detox while initially using this product, and some may not. This may be due to the release of stress on the body from EMF, and the immune system will normalize. We recommend you purchase a Premium Portable model to carry with you when you are away from your home or office. This will maintain a level of protection when you are away from your home protected zone.