SoundBlock Custom Bluetooth Wireless Stereo Speaker for Computers and Smartphones. Bluetooth 3.0 Technology with Built-in Speakerphone and 10 Hour Rechargeable Battery. in Blue/Black Great sound quality with apt+: high-fidelity stereo sound quality with apt codec and CSR8645 chipset. These headphones are compatible with most smartphones, iPhone and Android. The best battery playtime More stable connection with new Bluetooth 4.1 technology: compared to Bluetooth 3.0, 4.0, the latest version features faster & stable signal transmission, clearer sound quality and lower power consumption. Fully waterproof IPX7 Satisfaction