Review on Gowoops 2PCS 150W Adjustable Power Voltage Step Up Boost Converter Module: DC-DC 10-32V to 12-35V by Antonio Gonzalez

Basically a breakout board with a DC boost IC and the necessary external components. The FET they chose states XL6009 on the chip, making it an XLSEMI product, which is relatively new gear from Shanghai. There is no datasheet for the XL6009 itself, but I finally found it. The external components on what I got were: an input smoothing capacitor (35V max), a Schottky diode, an output capacitor (mine says 50V max), and a potentiometer to adjust the output voltage. I'm not sure you can really expect it to hit its 4A rating without significantly more cooling than this board. If you replace the output capacitor and diode with a higher voltage, you can easily get well over 35V. However, the ripple was pretty bad at 1.5A / 3.3V - depending on your application, you'll have to do a lot more than that just add a shunt cap (especially since this board already has a smoothing output cap). But there are many apps that aren't that sensitive and it's pretty cheap. My test efficiency from 5V to 12V with 2A input was only about 85%. Overall pretty good value for money when you know what you're getting.