This large WaveShield 3000 is used for cell phones or cordless phones. It's large diameter is need for lots of house phones and slightly larger cell phones. It's ability to stop cell phone radiation is just the same as all other models. The vast majority of electromagnetic radiation emitted by cellular and cordless phones comes from the antenna and parts of the phone other than the ear piece. Wave shield products have no effect on this electromagnetic energy. They may reduce the strength of electromagnetic-field emissions from cell phone ear pieces by as much as 50-97% depending on the cell phone model.