LumsingDirect via Amazon offers its Lumsing Harmonica 10,400mAh Dual-USB Portable Battery Pack in White for $19.99. Coupon code "3VVEVTHT" drops it to $9.99. Plus, Prime members bag free shipping. That's less than a buck over our May mention of another color and the lowest price we could find now by $5. It features two USB charging ports and a battery level indicator. Deal ends July 23.