Features:- Great for air current circulation, sweat-resistant and anti-fog- Can be installed at both right and left side of protective mask according to your comfort- Powered by 2 x AA batteries ( not included )- Made of high-quality TPU, durable to use How to use:- Press the open button for opening the lid.- Press the delaying time button for turning on the fan ( 8 minutes after turning on, the fan will turn off automatically to prevent the damage of the fan in case you forgetting to turn off ).- After stopping, there is no effect on turning on or off the fan again.- No need to take out the batteries while no using, it will be into a resting condition.Package weight: 0.123 kg Product Size(L x W x H): 9.20 x 9.20 x 5.80 cm / 3.62 x 3.62 x 2.28 inches Package Size(L x W x H): 10.20 x 10.20 x 6.80 cm / 4.02 x 4.02 x 2.68 inchesPackage Contents: 1 x Electric Fan Filter Tank