This keyguard fits the older Apple Wireless Keyboard, not the Apple Magic Keyboard.  You can order keyguards for that keyboard here (2015 - 2021) or here (2021-). 

This item does not come with a keyboard. This is to order the keyguard only.

This keyguard comes with no attachment method.  While gravity will hold the keyguard in place, most users prefer to stick it to the keyboard with tape or a mounting putty like Blu-Tack.  The is room for a small amount of suction cup tape.

Size - The default size of the keyguard is the same as the keyboard.  You may optionally choose to add an oversized flange which adds an additional rim around the perimeter, extending beyond the keyboard and containing optional holes which you can use to devise your own mounting method.  These holes are 0.19" in diameter and fit a #10 machine screw.  Our screw kits fit these holes.

Material - The keys are just under 1/8" high, so if you pick an 1/8" material, the top of the keys will be just below the surface of the keyboard.  Most people prefer a material of 3/16" or greater, to give a little depth to the holes, requiring a more deliberate touch. 1/4" materials make for even deeper holes. A popular choice is polycarbonate, which has a lifetime guarantee against breakage and nice, bevelled edges which make the keyguard softer to the touch.