Awakened Elemental Focus support and %Chance for Double Damage while focused

Please explain - is it working craft in Crafting bench: "%Chance for Double Damage while focused" on bow when I use Awakened Elemental Focus support gem on it as a support for Tornado Shot on my bow (Ice Shot or whatever ? Is it better to have than "13% increased attack speed" craft?

Thank you for explaination.

When you craft the "while focused" things it has nothing to do with support gems.
You get a skill "Focus" that you can then use and it triggers all your "while focused" effects

Thank you for the answer. However - I didn't notice items with Focus skill on it. Can anybody link few items with "Focus" in PoE trade shop ? I just don't know what is it...

https://www.pathofexile.com/trade/search/Crucible/9J3J5mQtK

When equipping an item like this, with "when focused" on it, you will gain a new skill on the bar called Focus. When clicked, all the "when focused" modifiers will apply, just like imanubcake said.