Is it possible that there is a mistake on the page and they mean 450 Watts?
The "1 ATR SHORT" version lists 2 modules and takes 300 Watts, so 450 Watts would line up perfectly for the "1 ATR LONG" which takes 3 modules. 4.5 kW doesn't make a lot of sense here.
The "1 ATR SHORT" version lists 2 modules and takes 300 Watts, so 450 Watts would line up perfectly for the "1 ATR LONG" which takes 3 modules. 4.5 kW doesn't make a lot of sense here.