This is an LM2596 DC-DC buck converter step-down power module with high-precision potentiometer, capable of driving a load up to 3A with high efficiency, which can work with Freeduino UNO, other mainboards and basic modules. When the output current keeps greater than 2.5A (or output power greater than 10W), please add a heat sink on it.
The difference between these and the other LM2596 module is that, this uses DIP capacitor and does not seems to have onboard LED. Also both the modules are different manufacturers, and hence different quality, but technically the same specifications.