The content is the big brother SAS Survival Handbook: How to Survive in the Wild, similar but slimmed down in any climate on land or at sea. For this you can the little book that the size of a cigarette box is always bring good, though a little heavy.
Content is very well prepared and the language is easy to understand.
Conclusion: If you want to know "everything" buys the big brother. Who wants to have a little book always with you is right with this stripped-down edition.