3 different earbud sizes The soft, silicone earbuds come in 3 different sizes for a tight seal and comfortable fit. High quality speakers To optimize sound quality for calls and music, we kept the speaker output structure at a narrow 3mm, so that detail in the mid and high frequencies are preserved and noise is significantly reduced. Bluetooth 4.1, reduces 4G network interferences The CSR8610 chipset supports Bluetooth 4.1, which reduce 4G network interferences, improving device compatibility, stability, and functionality across the board. Charging dock The included charging dock can fully charge the headset to full about 3 times. The charging dock itself includes a 320mAh battery and boasts a standby time of approximately 90 days.