Since the 2017 MacBook Air has the same design as the older MBAs, the feet from iFixit will (most likely) fit.
If you are still unsure, however, you could get these 100% rubber feet (which may last longer than the OEM) for the 2017 MBA on eBay:
[link|https://www.ebay.com/itm/295838885052?_skw=macbook+air+2017+feet&itmmeta=01J80XC9BNA7AYGSJQT4BR61VF&hash=item44e15f24bc:g:XAoAAOSwLY5e5rB1&itmprp=enc%3AAQAJAAAA8HoV3kP08IDx%2BKZ9MfhVJKmgADl8W%2F6XkuL0vdY1xsqh0df1ZfFzHqoJcw5J5ov%2FuqnvZxJhHQwEljZ96ff5IOAB3Z9hItnso116fcXx%2B0qvBLcQ7zpaZU3QUWjVG6%2FqlBYMNiO3Pbs0bbHvVYsYC7DMyR9bl3zwQP89r3AB8ViN%2BiTm7z00bcANNJFvrTJDd5%2FwZprstC%2F4mgq%2F0L0nkf5NeDFsUvxBYhk3vtUhcxN%2FHW0YqnJ%2B6XuTGmOoaYSIb63ChUskIzH3p8kLY2tiTrs4M%2BQOY8P5n%2FMZy1%2FPnkVac7OBIsXyu2ObJjisks3vHA%3D%3D%7Ctkp%3ABk9SR_qVsZ3AZA|New 4 Pcs Rubber Feet for Apple MacBook Air 13" - A1369 A1466 - 2010 to 2017|new_window=true]
Here is the iFixit (plastic) feet if you want to buy it:
[product|IF188-109|MacBook Air Plastic Feet (ifixit.com)|new_window=true]