Take Rechargeable Fresh Air With You Wherever You Travel. It’s finally here! The new USB rechargeable Air Supply AS-300R. With 28 hours of run time per charge, this ultra light weight, wearable unit propels cleaner, fresher and healthier air into your personal breathing zone. Created especially to help sufferers who want to breathe more easily when they travel. Ounce for ounce the AS-300R outperforms the competition and is top of the line in personal air purification. Has an advanced design. This Air Supply Rechargeable also comes with a breakaway strap.