I like the idea of having two colours in one pencil but it doesn't last well or go on smooth. Won't buy it again.

Good eyeliner. Not as smooth as some others and tends to get scratchy like some other wood pencil liners.

Extreme definition? Not really sure about that. The pencil eyeliner comes in dual shades that compliment each other.
I bought 009 Pink Princess and it is a frosty light pink on one side and dark violet on the other. To get extreme definition like the product is advertised for, you would have to line the same spot multiple times. With the multiple lining, it becomes cakey and flakes off. The eyeliner also smudges easily and the lighter colour end disappears throughout the day when worn.
It is not the best eyeliner but also not the worst.