Backcountry skiing is gear intensive. There are layers upon layers of clothing, skins, avalanche equipment, and whatever else the day calls for. I try to keep things as minimal as possible, without sacrificing any fun. That said, there are three items that come with me on every tour, in addition to my beacon, shovel, probe, and Backcountry Ski Repair Kit. These are my backcountry electronics:
Radio
A two way radio should be a part of everyone's backcountry touring kit. Radios are particularly useful for exploring new zones, communicating back to your partners after your ski run, and facilitating rescue. I bring mine even if my partners don't have one. Some ski patrols monitor channel 9-11. While you shouldn't rely on ski patrol to help you out in the backcountry, they may be able to assist. In a rescue scenario, your radio batteries will most likely outlast your cell phone. So, if you can get a text or call out, give the radio frequency or channel that you'll be on, which can make communication in the mountains so much easier.
My personal favorite is the BC LINK 2.0 radio from Backcountry Access. I've found that it's range and clarity is second only to VHF (dual band and tri band) radios, which often require a license.
Satellite Communicator
I haven't always carried an inReach in the backcountry. In fact, it wasn't until I came out really late one evening, and learned that my wife had called 911, that I bought one. Before then, I liked the idea of not relying on anyone for any situation I might find myself in. I liked being self sufficient. But as I've come to realize, skiing isn't all about me. Like a radio, having an inReach or similar satellite communicator is a lifeline. What if someone in your party gets injured and you have to spend the night out? You may have all the tools and knowhow to survive the night, but if you're unable to let someone know that you're ok, you could be unnecessarily facilitating search and rescue. I also like knowing that if my cell phone dies (my primary use for maps and navigation), that I can always use my inReach as backup.
The Garmin inReach Mini is great because I hardly know it's there at 3.4oz, and it doesn't break the bank if you're only using it for emergency situations.
Headlamp
I've come to embrace getting back in the dark. It's not always ideal, but having a headlamp makes it all the better. In short, knowing I have a headlamp in my pack, gives me peace of mind in the mountains, and allows me to push the limits of the day (morning or night). I recommend a headlamp with at least 400 lumens if you're going to be skiing in the dark. The Backcountry Ski Repair Kit comes with three AAA batteries, in the event that your headlamp [or beacon] dies before you're out of the backcountry.
I have found that the Petzl Actik Core is the perfect blend of lumens (450), lightweight, and functionality.
As always, make a plan and let someone know where you're going. Being prepared is the best tool for any backcountry adventure.