I bought this adapter to a stay in the USA in charge of another stronger adapter but had an earth ground ... For fear of meeting old taken without earth connection, I wanted to be sure I can recharge my devices in all cases. In the end, the two were used for 10 days without any problem ... Note that I've always left plugged into the same device to avoid disconnection / reconnection multiple and thus avoid spreading the cards (which remains the major problem with these devices). To see the long term but considering the price, you do not take a big risk in all cases ... So do not hesitate ... to 1 !!!
