Review on Dell D5G6M 7.4mm to 4.5mm Dongle DC Power Converter Cable, Compatible with 57J49 and 331-9319 for M3800 XPS Series, Inspiron Series, and More by Eric Beck

Update: Rating changed to 2 stars because I bought 5 of them and after 2 years all 5 stopped working. Some failed within a few months and the last one eventually died after about 2 years. So I think you have to buy them again and again. Works as advertised. Looks like a well made cable. My new Dell XPS 15 9560 is happy with this adapter which uses an older Dell PSU.