This is the hook, on loan from a lady who tells me it is Peruvian.
This is it in comparison to a 15 mm and a size Q
hook.
The difference is in the width between shaft and point of hook – and boy, does that make a difference!
First of all – the method of crocheting changes because you need a very loose tension on the left hand (I am crocheting right handed) to make the wide scoop.
Secondly - it is a WIDE scoop!
Here is how it looks in tunisian crochet (the bottom rows) and single crochet (the top ones)
It is fun!