NOTES FROM LUKE:
Despite being rated for 4A, I don't recommend these for more than a 3A load, based on experience with about a hundred of them.
SPECS: XTW6009 is a high-performance 400KHz 4A switch currency step-up (BOOST) module.
This module XL6009 is coming with the 3rd generation high-frequency switch technology as the core chip, The performance is much higher than LM2577. Wide input voltage: 3V~32V;
Optimum operating voltage range: 5~32V;Wide output voltage: 5V~40V;
With 4A high efficiency MOSFET switches, so the efficiency can be up to 94%, (LM2577current is 3A only);
With ultra high switch frequency 400KHz , even if small capacity filtering capacitors can achieve very good results, ripple is smaller (Compare to LM2577 frequency 50KHz);