5 US it’s perfect size. I purchased these for vacation. My kid wears to swim practice every time. I wanted to charge my phone with that front port, not look at the mouse bungee plugged in there in the front all the time. I expect these will last for many, many years even with heavy use. parfait ! 4- After like 15 times of using the headphones, they wont turn on anymore, and when I try to charge them the red light goes on but they dont hold charge anymore. They have a smooth top end and provide plenty of bass. And pretty on-par (quality wise) with my $130 wired earphones. Cord length is good .