Is there a more general word than "type" or "kind" or "style" that fits these sentences?
You can say
- "low sodium is a variety of soy sauce"
- "hatchback is a car model"
- "extra-strength is a dosage form of Tylenol"
- "rechargeable is a category of flashlight"
- "steel-toe is a type of boot".
But I can't think of any single word - other than type or kind - that fits all your sentences perfectly.