Average range of detection is 300-350 meters. However, this item is a monocular rather than a sight, so in part distance will determined by what sights you are using it with. If you are using it with a night vision compatible red dot sight, then it would mostly be down to your shooting skill. If you are pairing it with a magnified optic, the range could be further. Night vision is also highly dependent on ambient conditions by nature of the technology, so range will still be limited by factors such as fog/haze, precipitation, and ambient light.