EarFun PROFESSIONAL HIGH-DEFINITION AUDIO QUALITY AND SAFE VOLUME OF 85/94 DB: Your child will love the sound so clear and vivid, and the ears will be well protected. EarFun's 17 years of audio technology and 40 mm diaphragm guarantee clear and true-to-life sound reproduction. The ability to switch between 85 dB and 94 dB safe volume protects children's ears from too loud or too quiet volume. Fast and stable Bluetooth 5.4 connection (21 metres): EarFun children's headphones can be easily connected to mobile phones, tablets, desktop computers and other Bluetooth devices within a few seconds. So your children can enjoy a reliable connection during class, playing and making calls. The included 3.5mm audio cable also supports connection to Tonibox and other devices.; EarFun