In-ear headphones using Bluetooth 5.1 technology. The transmission is twice as fast as the BT 5.0 and the distance has been increased four times. It easily copes with interference on the 2.4GHz network. It is a fast and stable connection with low energy consumption. The battery allows for almost 30 hours of continuous music playing if we regularly charge them using the case. Light design and appropriate shape ensure comfortable use, combined with the weight of only about 3g, you hardly feel any pressure.