The cables themselves are of good quality, however they do not support "fast charging" at least not for my Samsung S7 Edge. I used it with my original Samsung Fast Charger that came with the device, however with original Samsung USB Cable the phone used to go from 0 to 100% charge in under 90 mins, but with this cable it shows in excess of 120+ minutes. So the sellers' claim of the cable supporting "Fast Charging" is not accurate.
Edit: After about a weeks use, I can say that the cables do not support fast charging whatsoever, normal charging only. I changed my rating to 1 star from 3 as the product doesn't do what it's mentioned its supposed to do and bought for.