Riddle: What has keys but no locks. Space but no room. You can enter, but can’t go outside LIMITED TIME OFFER! CORRECT

Riddle:

What has keys but no locks. Space but no room. You can enter, but can’t go outside
LIMITED TIME OFFER! CORRECT GETS A REWARD OTHER THAN POINTS! MESSAGE ME FOR REWARD WHEN I HAVE SAID YOU HAVE GOT IT RIGHT
ARE YOU ER THAN YOUR FRIENDS?