It is Breakout board for the Analog Device's ADXL345 Tripple axis accelerometer with Voltage regulator onboard. The module is populated with MOSFET based Voltage level conversion circuitry to enable you to interface different type of microcontrollers (3V3 & 5V) . Apart from the above all necessary components like decoupling capacitors , filter capacitors ,Pull up resistors and LED are also populated on board. So out of the box you are ready to go. The ADXL345 is a small, thin, low power, 3-axis accelerometer with high resolution (13-bit) measurement at up to ±16 g. Digital output data is formatted as 16-bit two's complement and is accessible through either a SPI (3- or 4-wire) or I2C digital interface. The ADXL345 is well suited to measures the static acceleration of gravity in tilt-sensing applications, as well as dynamic acceleration resulting from motion or shock. Its high resolution (4 mg/LSB) enables measurement of inclination changes less than 1.0°.