The knife for the TT4000+ thermal transfer printer allows the operator to cut the heat shrink tubing to the desired length. This enables quick and easy production of heat shrink markers of any size and with any print made on the printer, based on continuous heat shrink tubing (on a roll). The knife can also be used to cut labels, for example in continuous form. It is easily connected to the printer at the front. During startup, the printer automatically recognizes and initializes the knife. The collecting container is a useful addition, especially for small labels or heat shrink markers.