With incredible video quality, ease of use and powerful networking tools, Revo ultra is the very best that Revo has to offer. The Revo Ultra's superb video quality is based on IP technology. The RU42B4I-1T is a complete plug and play HD surveillance system with 4 CH 4K NVR, 1TB and 4x 5MP HD Indoor/outdoor Starlight Audio Capable Bullet Cameras. The Revo ultra NVR is powerful featuring state of the art H.265 Compression, up to 4K Recording and 4K video output. The H.265 Bullet Cameras feature massive 5 MP Starlight Sensors, 2.5 times the resolution of standard 1080p. The Starlight Sensor and the built-in specialty lens help deliver extraordinary low light performance. The cameras are equipped with a built-in microphone for audio streaming and recording. The built-in Professional Grade OSRAM LEDs and IR anti reflection glass strongly illuminate the scene up to an unprecedented 100 in total darkness. The RUCB36-3 Bullet Camera features a 4 mm fixed lens that provides an 80° wide angle of view. The cameras are built for the outdoors capable of handling temperatures as hot as 140°F and as cold as -40°F. The polished look and intuitive feel of the Ultra's interface is a joy for everyday use whether you're using the NVR itself, the Mobile App, Computer Software or Browser.