They fit perfectly on the stock Sony pad holders with the only tool needed is a small screw driver to pop the old pads off and a box knife or small pair of scissors to cut small holes for the alignment guides. Mayyyybe 2 inches across! The only reason I didn?t give 5 stars is because the elastic ?fake? laces came unraveled. They are simply not loud enough at all and if you put any sort of pressure on your ears or try pushing them in ears further to keep them in the noise diminishes even further. really good packaging. I use it on my road bike and juiced city scrambler. Disappointed, but bought a 2nd pair and just watch it a little and am back to jamming like a maniac. It makes it very easy for me to locate my air pods in my purse or just sitting on desk or table. I always worry about a surprise during recording. I got them on a very discount price but i wld return if paid full price.