The Bitter clamp is a popular device for cleaning tobacco stems during the cigarette manufacturing process. It consists of two parts: a conical upper removable part and a lower base that creates pressure. The upper part is attached to the center using two hinges. A spring is used to fix the needle on the other edge of the clamping device. When the top of the cap is closed, the spring is compressed accordingly and the needle is pulled inward, pressing against the tobacco leaf.