Technical maintenance should be done at least twice a year, includes the following steps:
Clean the outside metal and plastic surfaces from dust, dirt and moisture; wipe the scope with a soft lint free cloth. To avoid damage to the paint coating, do not use chemically active substances, solvents, etc.
Inspect the eyepiece lens, the objective lens, IR illuminator and rangefinder; gently blow off any dust and sand, if necessary clean their outside surfaces.