The connectors on either end are built to last as well, featuring a laser-welded metal construction with reinforced stress points to help resist splitting apart like some inferior cables. This is then shrouded in a two-piece protective shell consisting of tough plastic around the connector itself with a soft and flexible boot to reduce stress at the critical junction between cable and connector.
I've spent considerable time and effort trying to get these cables to show any signs of weakness and fatigue from deliberate misuse. I've bent them back and forth at the same spot, I've folded the cable back on itself at the vulnerable connector ends, and I've yanked hard on the cable and connectors. I'm clearly no match for these cables; you can't tell that they've been used at all. In fact, the PowerLine+ Micro-USB cable that I wrote about in January 2016 is still in perfect shape.
These cables work great, too. First and foremost, they include the correct 56k Ω resistor per the USB spec. This means that the cable will be able to safely charge your USB-C devices without the risk of the device trying to pull too much current from a USB-A port. Anker's product page also notes that these cables are compatible with Qualcomm's Quick Charge technology for fast charging of QC-equipped devices; devices like my own Nexus 6P are listed with "limited charging speeds" simply because they don't support Qualcomm's proprietary fast charging method and instead rely upon the rapid charging built in to the USB-C spec. Such devices will not be able to rapidly charge with this cable (or any other standards-compliant A-to-C cable) but will still charge as fast as USB-A allows. The point is that the cable isn't the limiting factor here.
That all being said, these are USB 2.0 cables with a maximum theoretical data transfer rate of 480 Mbps, quite a bit slower than the 5 or 10 Gbps boasted by USB 3.0 and 3.1. If you routinely use a cable to move data to and from your phone or other USB-C device, you might be better served by Anker's slightly-more-expensive USB 3.0 cables. If you, like me, live in The Cloud and primarily just use cables for charging with occasional data transfer tossed in every now and then, these USB 2.0 cables should do just fine.
I was a bit disappointed to see that the 2-pack is missing the super-convenient carrying pouch offered with the single PowerLine+ cables, but they do each sport a captive hook-and-loop strap to make short work of coiling the cables for transport. Built-in cable management is always a welcome feature.
All told, the Anker PowerLine+ 6ft USB-C to USB 2.0 Cable 2-Pack is a pair of fantastic high-quality USB A-to-C cables that will serve your devices well for years to come.