Works on either earbud - it perfectly works on either earbud. My previous buds control have all faced to the back, and were intuitive. I prefer beige color so I like it. I know that they come up bigger but common these are massive. It comes at an astronomical price that might even make you pass out at just one look, but sometimes if you want the best, you do whatever it takes to get it. The call is connected to the ?parts and service department? and asks you to leave your phone number and email. Phone call quality and phone only through right earbud--I find the call quality, both microphone and listening to be better than the AirPods and I use the SSFs for an hour or so of calls per day. Very bad quality for the price. I was so excited about these slippers as I was trying to find everyone a pair for Christmas but needed mine early. The spring loaded plate on the bottom does not move smoothly at all from a dead stop center.