These stickers are Z-Cube brand and are not factory original replacements. 

Make sure to grab some application tape, it makes re-stickering your puzzles as easy as 1,2,3.

To Apply Stickers:

1. Apply Application Tape to sticker sheet
2. Rub firmly to transfer stickers on to Application Tape
3. Carefully peel the stickers off of the original backing sheet
4. Place the Application Tape (with the stickers) on to your puzzles and press firmly
5. Carefully peel the application off of the stickers (which should stay stuck to your puzzle).

Alternatively you can visit our detailed article, here. With a great instructional video.