VFD004L21A is a model of the Delta VFD-L series variable frequency drive.

The VFD007S43A is a model of Delta frequency drive, which is designed to control the speed of an electric motor.

The VFD015S21D is model of Delta frequency drive.

VFD002S21A is a model of Delta frequency drive (inverter).

Delta VFD015S43D is frequency drive or inverter manufactured by Delta Electronics.

VFD004S21A is a specific model of Delta Frequency Drive, which is an inverter designed for motor control applications.