... mperature of this unit is 15-30 degree and it must be powered off after continuously working 2 hours to let ... it worked for a long time.6,do not usd the telescope to watch the laser rays,otherwise will be ... the grade of the laser for it is Class III B ,and will be dangerous if exposure to the ... 110-50-60HZ, 240V/if outside this range, it is recommended to use voltage stabilizing equipment, otherwise will ...