The Sony STR-KM5 is a home theater AV receiver that was released by Sony in 2013. It features 5.2 channels of amplification, with the ability to upgrade to 7.2 channels with the addition of an external amplifier. The receiver supports 4K Ultra HD video, as well as high dynamic range (HDR) and wide color gamut technology. It has built-in Wi-Fi and Bluetooth connectivity, as well as compatibility with popular streaming services like Netflix, Amazon Prime Video, and Spotify. The STR-KM5 also includes a variety of audio formats, including Dolby TrueHD, DTS-HD Master Audio, and Sony's proprietary Digital Cinema Auto Calibration (DCAC) technology. The receiver has a sleek and modern design, with a user-friendly remote control and intuitive on-screen interface. Overall, the Sony STR-KM5 is a versatile and powerful AV receiver that delivers impressive audio and video performance for home theater enthusiasts.