Has anyone used one of these before? I've seen them advertised online ranging from 5 to 16 litres per minute output flow, with up to 25 C temp increase. We were looking at the smallest unit, i.e. 5 lpm. Our main questions are:

1. Is that the max output flow rate? Or is that flow at max temp, which means it can potentially flow faster at lower temps?

2. Will it take mains water pressure as input?