Yes it is, sort of. The right earbud is the primary, so powering it on connects to your bluetooth source. When you power on the left bud, it connects to the right one. So you can put the right one in and just use it, but you cannot use the left one without the right one connected. Additionally, if you make a phone call, only the right one is used. You could connect both to your source and then take out the right one if you only wanted to use the left, but you will run the battery down on the right and you will need to keep it without range of your source so you don't lose connection.