The cable carries current; the adapter converts wall electricity into what the tool takes. Four Philips tools here supply the first and not the second, and a barrel-plug tool is the two in one unit.
Three things get called the same thing, and only one of them has a voltage worth reading.
A cable is wire and two connectors. It carries whatever is already there and converts nothing. A USB cable has no voltage of its own.
An adapter is the block that plugs into the wall. It takes 120 V from the socket and puts out 5 V over USB, and it is the part that decides whether anything happens at all. A cable with no adapter and no laptop is a cable.
A power supply with a barrel plug is both in one unit: the block and the lead are a single assembly, and its output figure is printed on the block. That figure is the specification — not the plug shape, which only tells you whether it will physically go in.
Two replacement supplies on this site show how precise that figure is: the BENSN states 12 V, 0.4 A for Braun shavers, the MEROM states 5.9 V, 600 mA for Braun clippers. Same brand, same kind of tool, and the two are not interchangeable. How to read input and output sets out what each number does.
Which of the three your tool needs is published. On the Philips OneBlade, the Multigroom 3000 and both entry rotary shavers, the listing states a USB-A cable and that the wall adapter is not included — so the tool needs something you already own to be a source. Why that is, and what USB-C changes, is a page of its own.
Check your own manual before you follow anything here. Temperatures, water ratings and supply voltages differ from model to model, and the maker’s own figures take precedence over anything written on this site. A supply of the wrong voltage is a failure rather than a slow charge, and the figure is printed on the tool — not inferred from a connector that happens to fit.
Last reviewed October 10, 2026