The function keys don’t send “F1”, “F2” etc. unless you hold down the “Fn” button (like “shift”). Instead they perform what on most keyboards would be a secondary function (adjust volume, etc.). For most people this is probably a better choice but if you use software which makes heavy use of function key shortcuts you’ll have to retrain your …

https://www.amazon.com/Apple-MC184LL-B-Wireless-Keyboard/dp/B005DLDO4U