Review from Amazon.co.uk:
5 out of 5 stars. 12 Jan. 2015
Outstanding - you won't regret buying it
Since others have written so eloquently and accurately about the quality of this item, I will merely say that having just received this, everything they say is correct. It's a quality item that allows you to use a simple wheel mechanism to identify which style will suit what chord and it's progression. On the inside there's information on Location 1, 2 and 3 and the seven styles available, e.g. Ionian through to Lorian. On the back page there's the chord reference chart. No space is wasted. It's also a quality glossy paper and should last a while.
In addition, when you receive the item further material to help is also provided. For example, the mode de-coder is also on YouTube. It was watching this that made me decide to buy. Having talked through the benefits of the item, Sion Wyn Morris, the creator, then begins to play and it's then that you see the guy's love of music and the guitar shine through. I like people like that. I also like that people like that are willing to share their expertise and help make one's own guitar development easier.
It's a good price, a quality product and will help your development. Recommended.