With incredible video quality, ease of use, and powerful networking tools, Revo Ultra is the very best that Revo has to offer. Revo Ultra's unique design complements any home or business. The Revo Ultra's superb video quality is based on IP technology which brings the power and beauty of digital high definition video right to the heart of your surveillance. The 2nd Generation 4 CH REVO ULTRA NVR features state of the art 4K Video Output, H.265 Compression, and support up to 4K Cameras. The 4 Indoor/Outdoor bullet cameras feature, optical grade glass, 3D Digital Noise Reduction, massive 4 Megapixel Sensors, double the resolution of standard 1080p HD. IR arrays illuminate the scene up to an unprecedented 100' in total darkness. Revo Ultra cameras are able to handle temperatures as hot as 140F and as cold as -31F.