Kindly Reminder: This bluetooth module can only support Android mobile device. Used to communicating between the VESC and VESC Tool (mobile) over BLE. Note that the UART port on the VESC must be enabled with a baud rate of 115200 for this to work. The UART port on VESC can work only under 115200 baud Operating voltage:2.0V - 12V Onboard Chip:NRF51822 Actual use distance:The distance to communicate with VESC is about 15 meters Frequency range:2.4GHz 2.4 GHz multiprotololl RF receiver ARM Cortex-M0 32 bit processor 256kB flash & 16kB RAM 2.0mm seven-pin four-wire connector length:90mm Antenna length:145mm net weight:3.5g Due to different batches, the appearance, color, and printed words of the product may vary, which does not affect its use. Type:V4 Colour:Black Material:composite materials Size:PCB size:27mm x 13mm Package Contents: 1 * Bluetooth Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.