Review on Anmbest 10 Pack AMS1117-3.3 Voltage Regulator: Efficient Step Down Power Supply Module for 4.75V-12V to 3.3V Conversion - 800mA Buck Converter by James Baker

These are linear voltage regulators, not buck/switching regulators. This means that when VIN is slightly higher than VOUT, they dissipate excess voltage as heat, so get hot and are not energy efficient. For example, if you use a 9 volt battery to power one of them, the regulator will get very hot, which is normal for linear regulators. However, they deliver a near-perfect 3.3 volts and only change by tens of millivolts when the load changes from 100 µA to tens of millivolts. mA if the transceiver is included in the radio project. So for me it's a lot better than other cheap linear regulators I've used in the past. So I'm deducting a star for the incorrect product description.