I have got these different Montserrat variations, but I only know how to define the simplest ones: regular, bold and italics.
This is mainly because I don't know what is the equivalent of a "black" font, in font-weight CSS property, for example.
Montserrat-Black.ttf
Montserrat-BlackItalic.ttf
Montserrat-BoldItalic.ttf
Montserrat-ExtraBold.ttf
Montserrat-ExtraBoldItalic.ttf
Montserrat-ExtraLight.ttf
Montserrat-ExtraLightItalic.ttf
Montserrat-Light.ttf
Montserrat-LightItalic.ttf
Montserrat-Medium.ttf
Montserrat-MediumItalic.ttf
Montserrat-Regular.ttf
Montserrat-SemiBold.ttf
Montserrat-SemiBoldItalic.ttf
Montserrat-Thin.ttf
Montserrat-ThinItalic.ttf