'Safe distance to technology' is the distance we recommend keeping your Qi-Technologies device away from any EMF source. EMF sources include electrical wiring in the walls, phones, laptops, etc). Safe distance is as follows: Qi-Shield: at least 1 ft. / 30cm Qi-Home Cell: at least 1.6 ft. / 50cm Qi-Max Cell: at least 3.3 ft. / 1m If you place your Qi device too close to an EMF source it will hinder your Qi device’s ability to create a working area of protection (and therefore stop your Qi device from working to its full effectiveness).