Our Level 1 All Brass Shields are generally used as auto or room Shields. There are 2 categories of Level 1 Shields. The most used type are used as Auto or Room Shields. They will reduce the amount of EMF in any space in which they are hung. Worn as a personal Shield, they will deflect EMF and other unhealthy energy. Because WiFi is so omnipresent in our suburbs, towns and cities, we generally recommend people start with a Level 2 Shield for personal energy protection.