Question about wireless charging

Hey,

I am getting myself the iPhone 11 and I am wondering what kind of wireless charging watt/speed is supported by it. I heard it used to be 7.5watts but is it 10watts now and if not, does 10w charger charge with 5w or 7.5w. Also, do I know what speed is it using? I cannot find answers to any of the questions above. Thank you.