MJ sports sunglasses, with case and USB charger. - Brand: MJ - Accessories: Case - Charger: USB charger - Storage bag: Storage bag Thank you for viewing. These are training glasses equipped with a unique flashing system. By putting a strain on your vision, you can train your dynamic visual acuity and instantaneous vision. They are also said to be effective for age-related decline in vision, and can be used not only by athletes but also by the general public. In addition to the main unit, a dedicated case, charger, and instruction manual are included. (If you play table tennis, we will include a special training method paper. Please inquire.) How to use video: https://youtu.be/EGXPBnNsurs?si=OcGj52U9wR_jMbYY