Kindly Reminder: This bluetooth module can only support Android mobile device. Used to communicating between the and Tool (mobile) over BLE. Note that the UART port on the must be enabled with a baud rate of 115200 for this to work. The UART port on can work only under 115200 baud Operating voltage:2.0V - 12V Onboard Chip:NRF51822 Actual use distance:The distance to communicate with is about 15 meters Frequency range:2.4GHz 2.4 GHz multiprotololl RF receiver ARM -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 , 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.