Patuoxun Ultra-Slim 10000mAh Dual-Port External Battery Charger Power Bank Pack for iPhone 5 4S 4… for $29.99
Amazon has Patuoxun Ultra-Slim 10000mAh Dual-Port External Battery Power Pack on sale for $29.99
This item should be the lightest external power bank around 10000mAh I've ever seen, only 7.83 ounces. Some similar items could be up to 10 ounces. Pretty light, considering it has a High Capacity. It may not seem like a big difference in weight, but if you have to lug this thing around in your pocket all day, it matters.
Today it's on sale at $29.99 (was $33.59)
In addition, save $5 on this item when purchasing 1 or more Qualifying items offered by Patuoxun using Coupon Code: 87X2CFX8
Total cost could be $27.53
The best seller of 10000mAh power bank on amazon is Anker Astro 3E 10000mAh Power Bank. It's $40 and 8.6 ounces, which is much more expensive and less portable than this one.
It seems that the products of this seller rarely go on sale, it's likely to be a temporary promotion.Company itself seems pretty reputable if you look at their reviews for other products