LED 670nM Red Light Torch Against Vision Deterioration Red Torch Red light against deteriorating eyesight. Regular "light showers" counteract age-related retinal fatigue. Such an LED torch with red light of 660-670 nanometres wavelength can possibly counteract the deterioration of visual performance in old age.  Specifications: Product name: Red zoom torch Wavelength of red light: 660nm-670nm Light colour: Red light 3 switch mode: High or Low or Strobe Size: 112x28mm Lens type: Frog eye optical lens Operating voltage: 3.7V Product material: Aluminium alloy Power supply: Built-in lithium battery (INCLUDED) Waterproof rating: IPX4   Package Included: 1 x Zoom red torch 1 x USB cable Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.