Review on RioRand 5 Pack Boost Converter Module: XL6009 DC 3.0-30 V to DC 5-35 V, Adjustable Output Voltage, Step up Circuit Board - 4A by Chris Hanson

works well, easy to use, probably factory or leftover. It was shipped directly from China. four of them were on the same board with breakage. Only + - input and + - output. four soldier glasses, two-sided. see four corners. a trimmer to adjust the tension [use a small flathead screwdriver]. consumes 17mA with no load. A standard 3-pin LM317t draws 2.5mA with no load. I believe it's safe for a load of 1A or less. The LM2596 chip itself (switching regulator) has an absolute maximum rating of 3A. I would try to somehow attach a radiator if the load is more than 1A. You have to get creative if you want to put a heatsink on it. No documentation is provided, so you'll need to do some searching, particularly on the LM2596 chip itself.