The lens heater is equipped with low, medium and high modes, which you can adjust the temperature according to different needs for condensation prevention. | Made of high quality material, the strip has the characteristics of rapid heat transfer and good heat preservation effect. | It runs on external USB power, which is convenient for use in the open air.It prevents condensation by warming up the lens on a camera or telescope. | Camera Lens Dew Heater Ideal for warming the lens, warming up the water bottle and bottle, and can also be used as a special wrist strap/knee to protect it from cold weather. | 1.5m USB cable length, dew remover warmer is very handy to use and you can connect it your power bank with a USB port.