Adopted from material, the USB wireless receiver is durable and use. You can connect the usb receiver and pair your device with it. It can transform your device into a fashionable wireless device, removing troubles of connection and allow you to use the ordinary non- enabled speaker equipment, listen to music from a smartphone or tablet wirelessly. Besides, compact design ensures it can be used in small space. Feature - Color: Black. - Material: Plastic. - Size: About 1.5 x 1.4 x 0.85cm. - Transmission speed: 100Mbps - Effective working diameter: 10m. - version: 4.1. - Working voltage: DC5V plusmn;0.5V. - Working power: 0.3W. - Transmission distance: ≧10m. - Working frequency: 2.4GHZ. - Transmission speed: 10Mbps. the usb receiver and pairing your device with it, it can transform your device into a fashionable wireless device, removing troubles of connection and allow you to use the ordinary non- enabled speaker equipment, listen to music from a smartphone or tablet wirelessly. - Easy to use: Turn-on automatically after plug-in usb charger, plug directly into the active speaker port with USB audio protocol or Through the 3.5mm audio cable, connected to speakers 3.5mm Aux audio port. - Powered by USB: 5V working voltage, ensure device working stably in a long time. - Compact design: It can be used in small space. Feature 4.1 technology, Audio Receive range reaches up to 20m in open space without obstacles. to audio output devices such as TV, , CD player, PC, MP3/MP4, and transmit audio to your stereo, headphones and speakers. Package list: 2 x Receiver USB Wireless Audio Receiver Car Adapter 3.5mm Aux Output for Home Stereo Speakers Amplifiers (Black)