Official samsung galaxy wireless charger.
As seen here: Samsung EP-PG920IBUGUS Wireless Charging Pad with 2A Wall Charger - Retail Packaging - Black Sapphire https://www.amazon.com/dp/B00UCZGS6S/ref=cm_sw_r_other_awd_7FSAwbGCHN33X
Same happened to me, I have been using this wireless charger for over a year, it works great with the Nexus 7 2013.
https://www.amazon.com/Samsung-Certified-compatible-smartphones-including/dp/B00UCZGS6S