StarTech.com USB To 3.4 to 5.5mm Power Cables - Type H/M/N Barrel - StarTech.com USB2TYPEM, The StarTech.com USB2TYPEM 1m USB Power Cable makes it easier to power 5V DC devices that have a Type M barrel power connector (OD: 5.5mm, ID: 2.1mm). You can power or charge the devices through an available USB port on your laptop or desktop computer.This USB power cable could save you having to carry around a separate wall adaptor in order to power or charge your 5V devices, such as certain external hard drives, streaming media players, and Bluetooth speakers.Backed by the StarTech.com lifetime warranty. StarTech USB2TYPEM 1m USB To 5.5mm Power Cable - Type M Barrel