SG90 servo is a custom 9g servo motor from M5Stack. This is totally compatible with the "8Servos" HAT and "PuppyC" base. This micro servo is very easy to use for beginners. There is no need to use a dedicated servo-drive board with feedback control and a complicated gearbox. Any common pwm driver or a microcontroller can easily control this servo. Compared to driving a stepper motor, a servo is much simpler to use. You can use it to do interesting small projects requiring angular movement and/or control. The commonly used pulse width is 1-2ms (-90° position - 1ms , 0° position - 1.5ms, 90° position - 2ms)，working at 50Hz. Going beyond the specified pulse width range will damage the servo.If you feel that the cable is not long enough, you can purchase the servo extension cable to extend it. The yellow wire is for the control signal, brown is for the ground, and the red wire is for the Vcc (voltage). Pay attention to the supply current and voltage to prevent the servo from getting damaged.