Description Model: Nordic nRF51822 Chipset: Nordic nRF51822 Dimensions: 15 x 15 x 1.6mm Bluetooth: BLE 4.0 Antenna: PCB-mounted antenna Operating Temperature: -25C to +85C Operating Voltage: 1.9-3.6V Transmit Power: +4dBm to -20dBm in 4dB steps Receive Sensitivity: -93dBm Multi-Protocol Support: BLE 4.x + 2.4GHz Transmit Current: 10.5mA Receive Current: 13mA Flash/RAM: 256KB/16KB Frequency: 2.400GHz to 2.4835GHz GPIOs: 6 System-on-Module based on the Nordic nRF51822 core Supports Bluetooth Low Energy, ANT, and 24GHz multi-protocols Bluetooth Low Energy protocol stack supports Bluetooth 4.x 11 general-purpose I/O ports with freely configurable mapping provide flexible peripheral usage. Rich peripherals: ADC, SPI, 2-wire serial port, UART Programmable Peripheral Interconnect () of the CPU Flexible real-time clock and two 16-bit and one 24-bit with counter mode Supports over-the-air (OTA) firmware updates Built-in 32.768 kHz oscillator (250 ppm) coprocessor, on-chip temperature sensor, random number generator, watchdog timer ARM -MO 32-bit processor, 256 kB Flash memory, 16 kB RAM Color: As Shown Material: PCB Package Contents: 1 * 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.