First warning is given when you have around 30-60 minutes of battery left. I love that these have the option to have a strap, no strap or ribbon. You have to keep it stable at certain position to work otherwise no sound through earbuds. All size fits all. Unfortunately, they are too wide for my narrow feet. It did as it was advertised. DEFINITELY a must buy for any rift s owners. The left ear produces a lot of very annoying static when the noise cancelling is on, especially when listening to someone talk in a video. Surprise on the quality of the phone. The build is rugged and seems like it will actually provide protection against drops (unlike cheaper silicone cases), though the charging port on the bottom is exposed so it wont protect against liquid ingress.