When it comes to hiding our secret things .we normally hides inside a bottle or in a box thats ok.!

But not ok always atleast for geeks because that is not 100% safe and also there is no interesting thinks in that so in this tutorial i am showing how i made a Book with secret knock lock. With this book we can hide your valuable things inside. no one can take anything without your knowledge because we close our book with a secret knock lock. So lets get start.