I've long understood that Yello-Bole was a sub-brand for Kaywoodie, reserved for briar which failed to meet Kaywoodie's high standards in the early 1930s. I also know that like Kaywoodies, the best briar was used in the 1930s 4-digit pipes. I came across this Yello-Bole 2109 and was impressed by its thick walls, substantial size, and grain. I'm smoking it for the first time after a light refurbishing and it not only smokes beautifully, but I'm quite impressed by the briar. I can find only a single, small, well-disguised fill. This is a "second"? I have 4-digit Kaywoodies that aren't this nice.