LM2596 Analog Control Buck DC-DC adjustable regulator module with LED voltage display, LM2596S power supply module, Step-down Voltage Regulator Module Input 4-40V, Output 1.25-37V Continuously adjustable,But input should be 1.5V higher that output Output 3A,suggest power over 15w pls install the heat sink The input and output voltage can display or be closed. With reverse connection and overheat protection and short circuit protection, Often use for DIY adjustable regulated power supply and other Fixed voltage out 12V turn to 3.3V, 12V to 5V, 24V to 5V, 24V to 12V, 36V to 24V