According to the Cellular Telecommunications Industry Association (CTIA), specific absorption rate, or SAR, is "a way of measuring the quantity of radio frequency (RF) energy that is absorbed by the body." For a phone to pass FCC certification, that phone's maximum SAR level must be less than 1.6 watts per kilogram. In Europe, the level is capped at 2W/kg while Canada allows a maximum of 1.6W/kg. The SAR level listed in our charts represents the highest SAR level with the phone next to the ear as tested by the FCC. Keep in mind that it is possible for the SAR level to vary between different transmission bands and that different testing bodies can obtain different results. Also, it's possible for results to vary between different editions of the same phone (such as a handset that's offered by multiple carriers).