Urgent need of help

So I got my msi z270 a pro MOBO thinking it would come with stand offs and mounting screws but it doesn't as I found out they come with the case. However I got my PC pre built for me 3-4 years ago and don't have any standoffs or mounting screws. My case is the cosair spec-01 does any body know what size mounting screw and standoff size I should buy as I can't seem to find an answer on the Internet.

Read this, will give you a idea https://en.wikipedia.org/wiki/Computer_case_screws

Got some screws from the local hardware shop hope they fit the motherboard and case when I install them