Leica TS11 User Manual page 125

Warning Potential hazards are not only related to direct beams but also to reflected beams
aimed at reflecting surfaces such as prisms, windows, mirrors, metallic surfaces etc.
Precautions:
Do not aim at areas that are essentially reflective, such as a mirror, or which could
emit unwanted reflections.
Do not look through or beside the optical sight at prisms or reflecting objects when
the laser is switched on, in laser pointer or distance measurement mode. Aiming at
prisms is only permitted when looking through the telescope.
TS11/TS15, Safety Directions 125