MacBook Air and MacBook Pro..

Yes, however theyre a horrible idea, theyll smudge up your screen, and some contain a bit of acids that will eat thru the anti-reflective coating on the screen.

advise highly against using them. Also they attract dusts like a fly trap.

Apple additionally now recommends against using these keyboard covers on current Macbooks:

"Leaving any material on the top case could result in damage to the display when you close it. This includes palm rest or keyboard covers, as well as any adhesive-backed keycap additions."

Some come in pretty colors etc. Some think it protects against spills which it really doesnt nor is designed for, it can protect against a quick splash......

However if your getting your macbook wet, you have other issues.

dont recommend any keyboard cover, theyre generally awful, collect dust and fuzz (as silicone does), they put pressure on the display.

They make nasty marks on the display. Theyre 5% function and 95% 'pretty'. and 100% a pain.

Of course, its your decision.