1/8" plug with threaded 1/4" adapter. From front to back, the buttons are: Power, Volume Down/Previous Track, and Volume Up/Next Track. The quality of these boots is absolutely ridiculous for what they cost. They are offered on the Amazon website as CHOCKALOTTA Best Fit in-Ear Replacement Ear Tips Upgrade for Plantronics Voyager 3200. It provides adequate sun protection while looking cute! The results were a bit inconclusive as positioning of the phone over the ear is critical, but the sound seemed better. It makes an unbelievable difference. Actually cheaper than the other items I have found online. I dont know how one reviewer managed to do this whatsoever. So the proof is in the pudding.