The Pololu 9V 1A STEP-DOWN D24V10F9 is a DC-DC step-down (buck) voltage regulator module that can convert a 9V input voltage to a fixed output voltage of 5V, 6V, 7.5V, 8V, or 9V. It is capable of handling up to 1A of continuous output current, making it suitable for powering small to medium-sized circuits. The input voltage range is 2.7V to 24V, and the module has synchronous rectification for high efficiency. It includes protection features such as over-voltage and over-current shutdown, reverse-voltage protection, thermal shutdown, and short-circuit protection. This module is 24mm x 11mm x 4mm in size and should be connected to the input voltage with leads or solder on compatible connectors. The output voltage is adjustable with a potentiometer or a single-wire serial interface.