Review on Compact and Powerful: Microsoft Surface Pro Charger for Tablets, Laptops, and Books - 65W Travel Adapter with 6.6Ft Power Cord (Black) by Marcus Hussain

It works, but with a lot of little problems. When plugged into an outlet (and NOT a tablet), the hum from the transformer is already audible enough to be uncomfortable. Not only that, but it also heats up very quickly and is quite hot. Both of these things can become a big problem with prolonged use and will likely break very quickly. When traveling there is no easy way to pack this without twisting the connection between the block and the cable and as it is non-detachable it will break over time. All in all a nice compact design that is redundant and also has transformer and heat problems.