Hello, I have the iPad air2 and it works wonderfully. It is also compatible with my cheap Samsung mobile phone. So I think it works with the air1 as well.
The keyboard weighs 810 grams.
I would buy the keyboard again.

Thank you very much for the answer. I have now ordered it and indeed: it works!
Only one key - the exclamation mark - gives + signs and I don't know how to change.
Otherwise I'm happy about it!