I recently got a whole bunch of Atari 2600 roms on my computer but I can't find an emulator to play them. Right now they are in winrar files, and the files inside have the extension .a26

I downloaded StellaX and PC Atari emulators but the files don't work. Does anyone have an emulator that supports these files? Or maybe the ones I have do and I am doing something wrong. Any help would be appreciated.