Pololu Step-Down Voltage Regulator D15V35F5S3 generates lower, user-selectable output voltages from an input voltage range of 4.5 to 24 V. It is a switching regulator and have a typical (when the output current is several amps) efficiency of approximately 90%, which is much more efficient than linear voltage regulators, especially when the difference between the input and output voltage is large. The output voltage defaults to 5 V and can be changed to 3.3 V by jumping 3V3 SEL.
Pololu Step-Down Voltage Regulator D15V35F5S3 has under-voltage and short-circuit protection, and thermal shutdown prevents damage from overheating. The board has reverse-voltage protection.
Pololu Web Site: https://www.pololu.com/product/2110