Adapters

so, you do not want to haul a converter - they're heavy. Converters convert the voltage. if you're bringing applicances (hair dryers, etc) you need to make sure they're DUAL VOLTAGE; if not, leave them.

otherwise, most everything else (cell phones, tablets, etc) already are, so you just need a plug converter. You can buy a universal adaptor, RS sells those - https://store.ricksteves.com/shop/p/travel-power-adapter or one specific for Italy and France - https://store.ricksteves.com/shop/p/european-power-adapter

First check your appliances and devices to see which are single voltage and which are dual voltage. Any that are dual voltage only need an adapter. If they are single voltage, then you need a converter AND an adapter. Consider buying dual voltage travel hair appliances and using a safety razor. Or leave your hair dryer at home and use the one provided by your accommodation.

A lot of applicances like hair dryers, curling irons, and shavers are dual voltage, that it, they will operate on either 230 volts in Europe or 115± in this country. These appliances have a switch to select the voltage you want to use. (Technically, the heating elements are designed for 115 volts. The switch puts pairs of them in series for 230 volts.)

We now see on the market "multi-voltage" appliance, which can operate on a range of inputs from 100 volts to 250 volts. They use transistors to limit the voltage "seen" by the heating elements. There's no switch, but the nameplate will say "Input, 100-250V, 50/60 Hz".

There are also Voltage Converters that work either way, some both ways. They no longer have to be heavy, as those old ones were dual volage transformers for high wattage appliance, like hair dryers. Now you can get multi-voltage converters that work for high wattage, non-electronic devices. However, the wave form from those multi-voltage converters is not a true sine wave and can damage electronic devices. For those devices you need a transformer converter. Those can be light weight by limiting them to about 40W.

I've even seen converter that have a switch to go between modes.

An adapter has a plug for that country on on end with a receptacle for a US plug on the other end.

The 3 pin plug for Italy is a grounding plug, for US devices with the third prong, a round grounding pin. This is the adapter you need in Italy for a device with a grounding pin.

Grounding plugs for France can be 2 pin because the French receptacles have a protruding ground pin that fits into a metal lined hole in the plug. This adapter will work in France (actually anywhere on the continent except Italy and Switzerland) for a device with a grounding pin.

Non-grounded devices drawing less than 2½ amps (575W on 230V), can use what is called a Europlug, which fits into any receptacle on the Eurpean continent. This is an adapter to use for non-grounded devices drawing less than 2½ amps.

I suspect that the chargers for your cpap an/or hearing aids are 1) multi-voltage, and do not need an additional converter, and 2) probably USB chargers that don't draw more than 2½ amps. If so, you can use a Europlug adapter with them.

My husband uses a cpap and we travelled to Europe last year with it. You need a device that is both an adapter (“adapts” the plug to fit the outlet) and a converter (“converts” the power). There are several on Amazon (European travel voltage converter) and is what we used.

Before you buy anything, look at every device and charger to see if they are dual voltage. If you're not sure how to do that, just ask. Don't assume because one person's device is not dual voltage that yours sn't either or vice versa.

And tell us what actual electrical devices you plan to bring.

My CPAP is dual voltage, and not even very new.
I haven't used a converter for years--most modern electronics are dual or multi voltage, but you do need to read the tiny label on things to be sure.

I will say that it has been longer than I can accurately remember since I last saw any hotel room in France or Germany which did not either have a hair dryer in the room (virtually all the time, sometimes in a place you might not think of such as the closet or what you might think is a desk but others see as a dressing table). Check all the drawers or ask the front desk. In the rare case that there isn't one, there will be one at the front desk or housekeeping will bring it up.

What I'm saying is save that bit of weight in your suitcase.

I found several travel CPAP machines online at cpap.com that use a multi-voltage (100-240V, 50-60Hz) power source. They have separate (brick) power supplies that are actually converters. The power supplies appear to draw less than 2½ amps and have non-grounding plugs, so a Europlug adapter would work all over Europe. You might even be able to get one with a European type C plug and not need an adapter.

Nigel, I stayed in a gasthaus in Berchtesgaden, and they provided a hair dryer in the room. It was dual voltage, and the key to move the switch between voltages was still attached to the cord. Why?

If anyone changed the voltage there, in Europe, and tried to use it on 230V it would not be good. Having the key with the appliance would only facilitate an American stealing it and taking it with them back to the USA.

We purchased Tessan adapters on Amazon, both 3 prong and two prong (and one for Britain). Since our phones and tablet are dual voltage, simply using the adapter was good. It also worked for my hearing aids. They have a regular plug and 2 USBs. They come in a number of configurations.
We’ve found that most places have hair dryers now.

I agree with Nigel...I don't think I've been in a hotel room in Europe in the last 10 years that did not have a hair dryer so you may not need to carry one with you. Check your curling iron for the dual voltage info people referred to above or maybe you can have a style where you don't need to use one?

Since our phones and tablet are dual voltage

They are not "dual" voltage. Dual voltage devices run on 115±V or 230±V, only. Phones, tablets, other USB devices work on any voltage from 100V (Japan) to 240V (Australia). I call that multi-voltage.

Manufacturers do this because it is cheaper to make one device that runs on any voltage source and just supply a different power cord depending on where the device is sold, than it is to make multiple single voltage devices with different power supplies for every group of countries.