The NJ310 delivers crisp, powerful bass and is a great companion for outdoor activities. The annoyance of realizing just before leaving the house that the battery is empty can be quickly overcome. With a charging time of only 15 minutes, the earbuds are ready for 70 minutes of listening pleasure; when fully charged, the NJ310B plays for a full 6 hours. The ergonomically shaped housing ensures a particularly firm and very comfortable fit, making the headphones an extremely comfortable companion. The included ear tips come in three sizes, allowing for a customized in-ear fit. Particularly practical is the integrated microphone, which enables hands-free operation of basic phone and app functions via voice control. By quickly pressing the on button twice during operation, the respective voice assistant on the playback device can be activated. This allows for adjustments to be made or information to be queried without having to pick up the smartphone.