This product, which uses tDCS technology to stimulate the brain, has been reported in papers to improve athletic performance. https://www.newsweekjapan.jp/yukawa/2019/12/halo-sport.php > Performance in sprint cycling improved by 17%, running endurance by 15%, speed and accuracy in piano practice by 30%, no serious side effects in over 32,000 sessions, jump power increased by 11%, problem-solving ability increased by 25%, the ability to multitask increased by 28%, surgical skills of medical students improved by 30%, posture improved by 5%, and hand dexterity improved by 10%, etc. ・This halo sport2 can be purchased for $392.04 including shipping (currently about 60,000 yen). ・Operation was confirmed on Android 15 on 2025-07-30. It has also been confirmed that the app can connect and music can be played. ・The Android app is currently unavailable on the Google Play Store. If you don't have the app, you can download the APK file from https://apkpure.com/halo-sport/com.haloneuro.halo/download and install it by double-clicking. ・It does not work on iPhones. ・There is no instruction manual, but you can basically use it by following the instructions in the app mentioned above. ・The ear pads are quite tattered. (Photos available) Crumbs will fall from the tattered parts. In addition, since it is a used item, there are scratches and stains. (Photos available) There are no problems in terms of practicality, but please refrain from purchasing if you are concerned. ・The cardboard box is the one that halo2 was sent in, reused. Paper used when Amazon products are delivered is packed to fill the gaps. (Photos available) If you are concerned about the dirt on the box, please refrain from purchasing. ・If you have any other necessary photos, questions, or requests, please comment before purchasing. ・If you have no questions or doubts, you can purchase immediately without commenting. We will give priority to those who purchase even in the middle of a comment exchange. ・Unreasonable comments may be deleted.