dodocool Headphone Charging Case with Built-in 500mAh Rechargeable Battery Micro-USB Cable

Features
Storage and Charging
Store and charge the earphone at the same time. Compatible with most wireless in-ear headphones with Micro-USB charging port. The built-in 500 mAh rechargeable lithium polymer battery lets you enjoy up to 16 hours of additional headphone playtime.
Quick Charging
You can simultaneously charge the charging case and your headphones. Or you can get up to 1 hour of headphone playtime from a quick 15-minute recharge.
Easy to Use
Just connect your headphone to the built-in Micro-USB cable, press the power button, and charging starts. You can also know the charging status and the battery level at a glance of the 4 blue LED indicators.
Strengthened Protection
The rugged yet stylish silicone material offers all-around protection for your beloved headphones and prevents them from bumps, dents, and scratches. Built-in over current protection, over voltage protection, overcharge protection, over discharge protection, and short circuit protection ensure safe charging.
Compact Portable
102.00 x 84.20 x 40.40 mm. Small and lightweight enough to be stored in your pocket, sport bag, or backpack. Convenient for carrying it on the go. Fit for gym workouts, running, jogging, cycling, climbing, and other indoor and outdoor activities.