Blow off valve / Dump Valve

Hi, I was recently looking up about small modifications that you can make to your engine to make it more 'efficient' and I came across something called a Blow off valve? Now I'm not very knowledgeable when it comes to cars but I know my small bits and pieces and I was basically wondering if I WOULD be able to fit one of these on to my 1.2 car? I've got my car specs below and a picture of my engine is also below. If I'm able to buy and fit one of these I would very much appreciate it if someone could tell me what one I should buy and how / where I should fit it. PLEASE take in mind this is purely for education purposes, I'm not in any way trying to 'chav' my car up, I just want to understand how they work better and potentially increase my MPG / HP if possible. Thanks.