Headphones
In early powered radios, the headphone was part of the vacuum tube's plate circuit and carried dangerous voltages. It was normally connected directly to the positive high voltage battery terminal, and the other battery terminal was securely grounded.
An IP68 rating means a device can survive against dust and up to 1.5 metres of water for 30 minutes. IP67: Offers a similar level of protection against dust as IP68. The main functions of the kids phone watch include Real Time GPS Position, phone call, video call, SOS Call, Voice Chat, Pedometer, Historical Route etc.
Jack or analogue cinch cables already provide the amplified sound signal. Via USB, so-called frames or data packets are transferred from the hard disk to the USB sound card and then converted and amplified in the speaker.