USB charging ports stopped working after about a year, but we were relying on this as a travel charger so they could have failed sooner if it was in constant use. I would not buy this again. 20180731 UPDATE: After I posted the review above, the seller reached out to me and replaced the flawed unit, and I have verified the USB charging function works again. I also put the old unit on a scope and discovered that leads 1 and 4 of the USB ports had a DC 0V differential (should be DC 5V), meaning the inside failed in some way, rather than something like the USB ports growing looser over time.