Note: Wireless means no video cables are needed for transmission. However, NVR and cameras must be connected to a power outlet for continuous 24/7 surveillance. Up to 16 channels can meet your subsequent expansion of monitoring needs. Flexible choice of 2.4/5.8 GHz WiFi networks for stable performance. Whether preview, video recording or playback, you can see it clearly with details. You can see up to 100ft even in low lights. Support auto-cascading and wireless relay, enhance connection distance and transmission distance. Rain, hail, and shine, this security system stays in any harsh weather conditions. Built-in mic and speaker, you can talk to visitors, delivery men, or others even if you're not at home. You can access this system directly through Alexa's voice commands, 100% hands-free voice control. This security camera can continuously monitor your home all day, guard your peace of mind. You can store videos in cloud storage, and watch them easily anytime, anywhere. 2TB hard drive pre-installed, max 8TB capacity meets your storage needs. You can share it with your family or friends, and you can view the video simultaneously.