I will abound in the direction of certain notices below the pedals is bad and not worth not even a small investment.
I bought the pedals because I was tired of having to give me even on Amplitube to play out on a real amp.
It is slow and recognizes the the low E when she has time. But the purpose of a tuner is given, and the famous low E, it is often difficult and time consuming.
I bought from a Fender PT-100, there's no photo: faster and more prcis. Him how it does its job.