Yes it's a real book....
See.
The Unbreakable® Umbrella made by real Self-Defence, is the secret agent tool you've been waiting to for. Just as strong as a steel pipe but only weighing between 590g & 822 g (depending on the model). With has no unusual parts, no more metal than an average umbrella, it does not arouse suspicion, can be carried legally everywhere, unlike a walking stick or cane it does not cause strange looks if carried by an able-bodied person, and it even protects against rain! Sadly it won't stop bullets, nor does it spray concussion gas at the twist of the handle.