Olympic arms pistol carbine mag

[Mr.Barty]

I'm looking at a Olympic arms carbine in .40 S&W that excepts glock 22 magazines but says they have to be converted.
I am I reading the text wrong as olympics site says nothing about comverting magazines.
And if I do need I convert them, what do you need to do to convert them?

I find this carbine on J&G sales.com under AR pattern rifles

 

[jerkface11]

There is no conversion needed on the 9mm gun.