Nắp che dao rọc giấy (Utility Knife Cover)

I know it's unimportant and difficult to print... but if you have the last few meters, you can print this.

There are two files... thick and thin... choose whichever suits you best... more secure when using a blade.

Note: I'm sure someone before me thought of this design... I apologize to them, I searched and couldn't find it.