Desktop wallet 4.2.5

Hello, 

i have a macbook and want to download the latest version of the desktop wallet i should be the 4.2.5 but i can´t open it with my Macbook ? Could it be that those download versions are only for Windows? 
I saw that the older versions files were .dmg but in the 4.2.5 there were no .dmg
Sorry it´s maybe a stupid question but i´m not that into that game. 
BR Alex