The Hollyland Mars 400s Wireless Transmission System (HL-MARS-400S) is a sleek black Bluetooth transmitter designed for wireless audio transmission. With a frequency range of 5Ghz and dual band capabilities, this device ensures reliable and high-quality sound transmission. It features an HDMI input and output connection, making it easy to connect to various devices for audio streaming. Weighing just 1.94lbs, this Hollyland product is lightweight and compact, perfect for on-the-go use in various settings.