Features: 1. It has I2S port and you can use the I2C port to control the volume and the frequency parameter. 2. It support 16 to 32 frequency data format. 3. It supports the high 384 kHz sampling frequency and dynamic range is 112dB with distortion factor -93Db. 4. With isolated power design, the Raspberry Pi power and DAC part of the independent power supply are isolated. 5. Common ground without disturbing each other through the beads, it can get rid of the current sound. Description: The sound card module has a high-speed switch design, which not only has ultra-low internal resistance, but also has low heat. Specifications: Transmiion distance: outdoor straight line distance 10-18 meter Battery capacity: polymer lithium battery 45mah Charging box battery capacity: 350mah Listening to music time: 1.5 hour Call time: 2 hour Standby time: 100 hour Charging time: 1 hour Color: Black Package Included: 1 * Sound Card Module Notes: 1. Please allow 0-1 inch error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from real object.