Outdoor HD Binoculars With WIFI Detection & Shooting Infrared Night Vision Device, NV31821. Power supply: you can use a power bank to supply power directly or use 6 AA batteries (batteries not included) 2. Effective viewing distance: 400 meters 3. Objective lens diameter: 30 mm 4. Working voltage: 9 (V) 5. Magnification: 4 times 6. You can use the AV interface to link external display devices 7. Scalable TF card up to 32G 8. FMC multilayer coating objective lens, clear imaging 9. Weight: 600 grams 10. Dimensions: 206x138x58 mm