The product is as good at it gets. Weighs ca. 65g, the material and cable are hard and solid enough. Power specs: 5V/1.5A in-/output, 3000mAh/11.1mWh battery. When charging a 5V/1A device, due to conversion and losses it delivers 67% of the capacity (a very decent result, enough to fully charge the 2000mAh battery of a cell phone).
Could prove even more useful if the input cord had a dual USB-A/USB-C plug, like the Xoopar MrBio product.