The ninth edition of Mountaineering: The Freedom of the Hills, published in 2017, defines the Ten Essentials as:

Navigation: map, altimeter, compass, GPS device, personal locator beacon
Headlamp: with LED bulb and spare batteries
Sun protection: sunglasses, sun protective clothing, sunscreen
First aid: a first aid kit, wrapped in waterproof packaging
Knife: hikers on a short trip may also carry a multi-tool, strong adhesive tape and cordage; on a longer trip, further small tools may be useful
Fire: the means to both start and sustain a fire; either a butane lighter or matches, or other fire making device. Firestarters for igniting even wet wood, and in areas where no firewood will be available, a stove is highly advisable.
Shelter: plastic tube tent, jumbo plastic trash bag or bivy sack
Extra food: at least one day's food for a short hike, that should require no cooking.
Extra water: drinking water and the skills and tools to purify water
Extra clothes: additional items may be needed if spending the night in the emergency shelter

https://en.wikipedia.org/wiki/Ten_Essentials