Have to share. At lunch today I saw a sushi chef unroll these cucumbers. Talking fast, three feet in two seconds, over and over and over. I was like this guys got game. He wasn't using a usuba either, was yanagibi but has two clips on it that act as guides, keeping the knife the right distance from the board. The clips didn't look professionally manufactured wither. Looked to me like some strips of plastic folded over the knife attached with tie wraps. I might be showing my naiveté here as I don't work in a sushi kitchen. Thought it was pretty interesting.