- Description Wireless on-ear headphones with JBL Pure Bass sound The JBL Tune 520BT headphones stream powerful JBL Pure Bass sound thanks to the latest 5.3 BT technology. Easy to use, these headphones provide up to 57 hours of pure pleasure and an extra 3 hours of battery with just 5 minutes of charge. Download the free JBL Headphones App and customize your sound through the EQ, while Voice Prompts guide you through the headphones features. Manage calls, sound and volume from the earcup, thanks to the convenient button control. If a call comes in while you are watching a video on another device, the JBL Tune 520BT seamlessly switches to your mobile device, so you never miss a call. Lightweight and comfortable even after hours of listening, the JBL Tune 520BT headphones fold flat in your backpack to follow you everywhere. General Specifications Driver size (mm): 33Number of Microphones: 1Audio Specifications Driver sensitivity at 1kHz/1mW (dB): 102 dB SPL@ 1kHz 1mWDynamic frequency response range (Hz): 20 Hz – 20 kHzImpedance (ohms):30Dimensions Weight (g): 157Weight (oz): 5.54Battery Charging time (hours from empty): 2Maximum play time (hours): 57Features Charging cableFoldable, Built-in Microphone, Hands Free Call, JBL Pure Bass Sound , Multi-Point Connection, Voice Aware, Speed charge, Bluetooth