A Caffeine tablet with apparent 'cult' status, used by students for years to stay awake while studying or during allnighters. Sometimes gets abused by people using it as a recreational drug - even though it's not great.
person 1: Man, I stayed up all night to finnish this!
person 2: Really? I thought you were gonna crash, you looked knackered before you left
person 1: yeah, but when I got home, I had some pro plus, woke me right up :)