The Green Lion Echo Max Headphones are splendid in sound and predictability. The Bluetooth 5.3 ensures a maximum range of 10 meters and a good frequency quality ranging from 20 Hz to 20 kHz for a refined sound. The 40 mm magnets with 32Ω provide a potentially balanced audio signal, while 102 dB of sensitivity allows for significant levels of clear, full audio. The 500 mAh lithium-ion battery lasts in Bluetooth mode for 50 hours on an average of 50% of its volume. It also has other features: a built-in mic, 48-hour playtime, and USB-C/USB-A charging for use.