A phone specification can tell you how large a screen is. A SAR result answers a narrower question: how much radiofrequency energy was absorbed per kilogram under a particular laboratory test condition?
Start with the test, not the color
Specific absorption rate is expressed in watts per kilogram (W/kg). Our US comparison cells use values reported in RF Safe’s database against the FCC’s localized 1.6 W/kg limit averaged over one gram of tissue. European head and body values generally use a different ten-gram averaging method and a 2 W/kg limit. Those two test systems should not be mixed in a single ranking.
Head, body, hotspot, and simultaneous-transmission values represent different use configurations. A simultaneous value may include more than one transmitter operating together. These are separate reported results; do not add the head and body numbers together or interpret their difference as an exposure reduction you will experience.
A comparison aid, not a health score
Our colors make differences within the same measurement easy to see. They do not label a phone safe or unsafe. Zero and missing values are shown as unavailable, rather than receiving a favorable color. A lower listed maximum does not guarantee lower everyday exposure: power control, reception, data traffic, distance, positioning, and active radios all matter.
Check the exact model
Regional hardware and FCC identifiers can differ even when the retail model name is the same. Match the identifier and consult the manufacturer’s separation instructions. Our specifications retain RF Safe’s source records; older launch prices, operating systems, and availability descriptions are historical, and unverified dates are identified.
Use the comparison to ask better questions, then pair it with practical habits: more distance, less unnecessary transmitting time, and wired connections when practical.