SAR stands for "specific absorption rate". SAR is expressed in units of watts per kilogram (body weight) (W/kg). The SAR value of a cell or smart phone indicates the maximum degree to which the head may absorb electromagnetic fields during a phone call with the device.
All manufacturers check to ensure that their cell and smart phones comply with the exposure limit and publish the maximum values measured as the "SAR value" in their operating guides.
You will find information about the SAR levels of Deutsche Telekom's cell and smart phones at: www.telekom.de/sar-werte, in Telekom Shops, at Telekom Trend and in the manufacturers' operating guides.