The Zebra GK420t is a thermal transfer printer that uses ribbons for printing labels and other items. Here are some key points regarding the ribbon for the GK420t: Ribbon Specifications Type: Thermal transfer ribbon Width: The ribbon width should match the width of the labels you are using. Length: Typically, the ribbons are available in lengths of around 74 meters (243 feet). ... https://theprintcartridgeshop.com.au/product/zebra-gk420d-direct-thermal-label-printer-usb-ethernet-interface/