Keep fog, dew, and condensation from forming on your camera or telescope lens with this 19.7" USB Lens Heater from Neewer. The heating strap wraps around lenses up to 126mm in diameter and warms the glass with power supplied by an integrated 4.9' cable to a 5V/2A USB-A port. The temperature regulator provides three settings: High Mode (131-149°F), Middle Mode (113-131°F), and Low Mode (95-113°F). The warmer secures around your lens via touch fastener. In a pinch, it can warm up a baby bottle or cup of coffee, too.