Lenovo K53b36 Quick Start Manual page 8

distance of 10 mm between the unit and the human body. Carry this
device at least 10 mm away from your body to ensure RF exposure
level compliant or lower to the reported level. To support body-worn
operation, choose the belt clips or holsters, which do not contain
metallic components, to maintain a separation of 10 mm between this
device and your body.
RF exposure compliance with any body-worn accessory, which
contains metal, was not tested and certified, and use such body-worn
accessory should be avoided.