Hi there!

There are currently 2 Belkin charger references. This is the first version (ref :
WIZ009) which limits fast charging on apple watches up to gen 6. The new, more expensive model (ref: WIZ017) allows fast charging of new Apple Watches from the 7 series onwards. Both are fully compatible with all versions of apple watch. The only change is the charging speed: 0-80% in 45 minutes for the new models, slower for this one.

The watch is fully charged in approx. 1 hour

Hello, unfortunately I can't answer how quickly, as I usually go to bed at 00:00 and by 05:00 my Apple Watch is 100% charged.
I can only recommend this charger :-)