It says it right there:
"The wireless charger automatically adjusts between 5, 7.5, and 10 watts to ensure your Qi-enabled device charges at the optimal speed."
5 watts is standard wireless charging, 7.5 watts is "Apple Fast" and 10 watts is "Fast for most." I seem to recall there being a 13 watt fast mode, but I may be wrong there. Been a while since I paid so much attention to this kind of thing. Anyway, it doesn't seem like a bad value, considering that the retail price of a Samsung 9 watt "Fast Wireless Charger" is about $55 and you only get the wireless charge mode. You can usually find those for around $30ish, but again, it's just the wireless charging. This has more options. I think I'll grab one!