This is a 'pencil ledgestone'. Each row is at least 1/3 narrower than standard ledgestone. It is natural material and can chip with weather, so use in protected areas.
My supplier was Marme in Toronto but not sure if they still have it- as this may be 2 years old now.
The colour/style is called 'Thinstone Autumn Brown'. Hope this helps with your project. All the best.