✔ Perfect Fit. Only Compatible with Bose Frames Alto S/M M/L, Rondo, Soprano and Tenor Models only. Standard USB Type A connector offers versatile charging ✔ Power Protection Inside (PTC). Easily plug it into USB port on your PC, laptop, notebook, wall charger or car charger to charge. ✔ Premium Quality. Adopted eco-friendly TPE and TPU material, the flexible cable ensures tangle-free operation. Flexible tangle free cable and exquisite metal connector is durable, making it sufficiently robust for even the most demanding users ✔ Lightweight and Portable. Compact and lightweight design makes it easy to store and carry. DC ripple is small, high efficiency, fast charging, the working temperature is low, long service life. Worry and save trouble! ✔ Excellent Service: All E ECSEM products have been checked one by one before sending to warehouse, please rest assured and enjoy . if you get a defective item, please contact our at the first time,. we are responsible for all quality-related issues