four single operate buttons, POWER/ MODE/ TARE/ PCS to make it easily operate and wide weigh range grams, with units between g, oz, ozt, dwt, ct, gn. (NOTICE: When the scale is inaccurate, to calibrate method as below: Press and hold M to enter calibration, press M again to get into calibration mass, then press T to cycle through calibration masses. While mass value is still flashing, add weight and press M again and it will say PASS and calibration is done