VEVOR 200W Foldable Solar Panel, 24% High-Efficiency Portable Monocrystalline Solar Panel Charger with MC4 Output, USB-A, Type-C & DC Ports, IP67 Waterproof for Power Stations, Camping, Hiking Trips
Yes, you can easily reach 400 W by adding a second panel. In most cases you should connect them in parallel using MC4 Y-splitter cables — no special electronics required, just the correct MC4 adapter cables.