A sleeping bag is easiest to choose when you start with the trip, not the model name. Think about the lowest temperature you are likely to face, whether you sleep warm or cold, how much packed weight matters and what protection your shelter provides.
For warm conditions, the Carinthia Eagle and Tropen sit at the lighter end of the range. The Defence 1 is another compact option where a modest amount of insulation is appropriate.
The Defence 4 is the better starting point for colder trips. For more demanding winter use, look at the Survival One, but check its extra bulk and weight against how you travel.
Temperature figures are a guide, not a guarantee. Clothing, sleeping mat insulation, wind, moisture, fatigue and food all affect how warm you feel. Compare the comfort rating first, then confirm the bag length, packed dimensions and weight on the product page.
If your trips cover very different seasons, a liner, bivy and compatible bags can make more sense than one oversized bag used all year. That approach gives you more control and lets each part dry separately.
Before ordering, check the current specifications and available variants. If the choice is still close, tell us where and when you plan to use it and we can help narrow the field.