Generation 1 tube night vision monocular, 2x with 42mm objective lens, compact and can see up to 200yds under star light, built in IR reach to 35yds Notice: Please use it in dim light and never use it in strong light.In strong light environments, always make sure to cover the lens cap to prevent the device from being exposed and unusable。 It is normal for generation 1 photomultiplier tubes to have black dots.