E-smart High Power Green Laser Pen - Black (1 x 18650)
Working temperature: +15'C~+35'C (In winter if temperature is low outside of room please warm up the laser pen inside room for 5 mins). Storage temperature: -10'C~+40'C; Cautions: Keep out of reach from children. Avoid directing eye exposure to laser beam. Don't keep the laser on continuously for more than 30 seconds or it will get burnt from inside easily.